From aid for Israel to abortion to Medicare, Sen. Rand Paul (R- Ky.) has been shading, changing or dropping some of the positions he espoused as a tea-party-backed candidate and as a new senator. (Chip Somodevilla/Getty Images)

Sen. Rand Paul wanted to eliminate aid to Israel. Now he doesn’t. He wanted to scrap the Medicare system. Now he’s not sure.

He didn’t like the idea of a border fence — it was expensive, and it reminded him of the Berlin Wall. Now he wants two fences, one behind the other.

And what about same-sex marriage? Paul’s position — such marriages are morally wrong, but Republicans should stop obsessing about them — seems so muddled that an Iowa pastor recently confronted him in frustration.

“With all due respect, that sounds very retreatist of you,” minister Michael Demastus said he told Paul (R-Ky.) after the senator explained his position during a stop in Des Moines.

Paul has built a reputation as a libertarian ideologue, a Washington outsider guided by a rigid devotion to principle.

But his policy vision is, in fact, a work in progress. While he has maintained his core support for cutting spending and protecting Americans’ privacy rights, Paul has shaded, changed or dropped some of the ideas that he espoused as a tea party candidate and in his confrontational early days as a senator.

As the prospect of a 2016 presidential bid looms larger, Paul is making it clear that he did not come to Washington to be a purist like his father, former congressman Ron Paul (R-Tex.).

He came to be a politician, like everybody else.

This transformation carries enormous risk. As Rand Paul seeks to broaden his appeal, he may damage his image as an authentic non-politician who is unafraid to stand up for his beliefs.

“The question is, is this guy a political genius or not?” said John Samples, a vice president at the libertarian Cato Institute. “Can he pull this off?”

In Samples’s view, Paul wants to win over as many voters as he can “without selling out.”

So what, exactly, does Rand Paul believe?

Sen. Rand Paul (R-Ky.), criticized the program that allows local police to receive military-grade weapons from the Defense Department during a Senate Homeland Security Committee hearing on Tuesday. (AP)

To answer the question, The Washington Post reviewed Paul’s speeches, his op-eds and the 326 pieces of legislation he has authored. (Just one, a minor amendment on presidential nominations, has made it into law.)

The Post also interviewed several Paul advisers. Paul’s aides declined to make the senator available for an interview.

Taken together, these sources provide a picture of Washington’s most intriguing politician — a candidate still tinkering with his platform, even as he stands on it.

Foreign policy

Paul’s evolving views have been on display most recently amid the national debate over how to confront the brutal Islamic State.

In June, when the militants had already seized large swaths of Iraq, Paul seemed skeptical about the value of targeting them with U.S. airstrikes.

“I’m not so sure where the clear-cut American interest is,” he said on NBC’s “Meet the Press.” He noted that the Iraqi military had folded in the face of the group’s attacks: Why should the U.S. military have to intervene?

“What’s going on now, I don’t blame on President Obama. Has he really got the solution?” Paul said. “Maybe there is no solution.”

But more recently, after the videotaped beheadings of American journalists, Paul has come out in favor of airstrikes and other actions to “destroy” the group.

“If I had been in President Obama’s shoes, I would have acted more decisively and strongly against” the Islamic State, he wrote in Time magazine this month. “I would have called Congress back into session — even during recess,” to ask for explicit authorization.

This was a stark change of heart. But Paul’s advisers say it did not signal a change in his basic philosophy on foreign affairs.

“He’s been characterized as an isolationist,” said Rob Givens, a retired Air Force general living in Kentucky, who has become one of Paul’s advisers on foreign affairs. “He’s not. He’s a realist.”

For Paul, advisers say, being a realist means he is skeptical of every possible military action, until he is convinced that there is a crucial U.S. interest at stake and that the action will succeed.

They said the senator has tried to study up on realism, looking both at instances when American presidents chose not to intervene (such as Dwight D. Eisenhower declining to save the French at Dien Bien Phu, Vietnam, in 1954) and at times when they gave the green light. Advisers said Paul has particularly studied Ronald Reagan’s decision to invade the island of Grenada in 1983 and George H.W. Bush’s invasion of Panama in 1989.

In the case of the Islamic State, one adviser said, Paul eventually saw enough to justify a president giving the go-ahead there, too.

“I think it was partly the beheadings. I think it was partly what was coming to be a consensus as to what a danger they were,” said Lorne Craner, a foreign policy staffer from both Bush administrations who has been advising Paul.

This was not the first time Paul made a public reversal on a matter of foreign policy. In 2011, in his early, fire-breathing days as a senator, he proposed eliminating all U.S. foreign aid — even aid to Israel, considered sacrosanct in the Republican Party.

But after an outcry, he soon altered his proposal; he wanted instead to cut all foreign aid, except for $5 billion a year.

Why $5 billion? A Paul aide said that amount would give Israel its full share — more than $3 billion per year — and still have money left over.

“We didn’t necessarily want it to seem like it was just for Israel,” said the aide, who spoke on the condition of anonymity to discuss internal thinking. “We should have enough for more flexibility. Maybe Israel needs more aid. Or maybe we come across another part of the world where it does make sense.”

Last month, though, Paul seemed to deny that he’d ever tried to get rid of aid to Israel. “I haven’t really proposed that in the past,” he told Yahoo News. Aides said he meant that he’d never actually submitted legislation to cut Israel’s aid — the idea had been floated in a budget proposal that was never formally introduced as a bill. Still, the fact-checking Web site PolitiFact gave Paul’s denial a rating of “Pants on Fire.”

Paul’s ‘utopia’

On domestic policy, Paul continues to advocate for deep cuts to the size of the federal government.

For one thing, he wants to eliminate four Cabinet departments: Energy, Education, Commerce, and Housing and Urban Development.

Paul’s plan would save some functions within those departments: The National Weather Service, the Census Bureau, the Patent and Trademark Office, and Pell Grants for college would all survive. But he would dismantle the bureaucracies around them.

That might save taxpayers tens of billions of dollars. However, it would also eliminate programs that provide money for things ranging from low-income housing to renewable-energy research to poor school districts.

“I’d leave it at home,” Paul said of the tax dollars spent on education in particular. Speaking at a University of Chicago forum this year, he said the money that flows through the federal Department of Education would be spent better by state and local school authorities. Of the department’s bureaucrats, he said: “They hinder innovation. I would cut them out of the loop. I don’t think you’d notice if the whole department was gone tomorrow.”

Paul also says he wants to privatize the Smithsonian Institution, which receives about 70 percent of its funding from the government. And he has urged an end to the Transportation Security Administration, saying airport security should be transferred back to private contractors.

Paul’s aides said he knows he may not achieve all these cutbacks. He has been in Washington long enough to understand that even small cuts in federal spending can be difficult to make.

“Rand’s a pragmatist. He realizes we’ve got a really large federal government,” said one of Paul’s longtime friends and advisers, who spoke frankly on the condition of anonymity.

“I think that Rand has a picture of what a utopia would look like,” the friend added. “And he’s very realistic about how long it would take to get there.”

So what is that utopia, in Paul’s mind? His friend said it would look like 1792, with the government that existed just after the Constitution was ratified.

“You’d have a smaller federal government, where the presidency is probably the weakest branch; you’d have a robust Congress, led by the House of Representatives,” the friend said. “You’d probably have a heck of a lot less taxes.”

The friend said that in Paul’s ideal world, unlike in the real 1792, there would not be slavery.

Beyond making cuts in spending, Paul has called for curbing the reach of government surveillance programs. He has spoken out against “roving wiretaps” — which allow investigators to tap a suspect who switches from phone to phone without getting a separate warrant for each one — and against the bulk collection of Americans’ telephone records.

It is less clear, however, where Paul stands on one of Washington’s touchiest issues: Medicare.

In 2012, he called for an immediate change in Medicare, which provides government-run health insurance to seniors. At that time, he had introduced an even bolder version of the reforms proposed by Rep. Paul Ryan (R-Wis.).

Both Paul and Ryan wanted to replace the current Medicare system with one in which the government gave subsidies to seniors and let them buy coverage from private insurers. But Ryan’s plan had a provision designed to quiet its critics: It allowed current seniors to remain in the old Medicare system, rather than forcing them into a new one.

Paul’s plan didn’t have that feature. It put seniors into the new system with much less delay.

“[For] everybody who is Medicare-eligible, this will be the new Medicare,” he said then.

A reporter asked: “What do you say to Democrats who say you’re ending Medicare as we know it?”

“We’re giving them something better,” Paul said.

Now, two years later, he is working on a different plan for Medicare, an aide said. Details haven’t been finalized, but the aide said Paul might propose preserving the old Medicare system after all.

Paul himself, speaking in Iowa City last month, seemed to indicate that he’d lost his desire to force seniors into a new system.

“Those of you on Social Security and Medicare, nothing will change,” he said. The only changes he mentioned would affect younger people, such as raising the age at which they would be eligible for Medicare. “My generation will have to wait a little longer to get it. It’s the only way you fix it.”

Social issues

Paul’s challenge is evident from the growing suspicion among social conservatives, who are skeptical of some libertarian views and have been questioning his commitment to their causes. These voters, a key part of the Republican base with sway in early-voting states such as Iowa and South Carolina, would be crucial should Paul run for president.

On abortion, for instance, Paul previously presented himself as an ardent opponent of the procedure. Last year, he introduced a bill that would declare a fertilized egg a human being whose life is protected by law.

But earlier this year, he seemed to acknowledge that such a proposal was unlikely to become law anytime soon.

“My religious and personal belief is that life begins at the very beginning,” Paul said at the University of Chicago forum. But, he added, “I think where the country is, is somewhere in the middle and that we’re not changing any of the laws until the country is persuaded otherwise.”

For many anti-abortion groups, that sounded like Paul was ready to concede defeat.

“We want somebody that’s going to be as assertive on the pro-life issue as abolitionists were on the slavery issue,” said Bryan Fischer of the American Family Association, which opposes abortion. “The question is going to be, how proactive would [Paul] be? And I think there are questions about that, if he believes that the American public is not ready to decide that issue.”

Similar questions have arisen about Paul’s approach to same-sex marriage.

While he has said he opposes same-sex marriage, he has also said the issue should be settled in the states, not in Washington. And he told the New York Times that the GOP ought to “agree to disagree” on such issues, in order to welcome a broader coalition into the party.

In Iowa, Christian radio host Steve Deace said some are already worried that Paul is trying to appeal to both sides of the argument.

“You’re asking too many girls on a date, man. And sooner or later, they are all going to start talking to one another. ‘Oh, wait. He called you, too?’ ” Deace said. He said that when he asked his listeners to identify a Republican who would fight for their views, most picked one of Paul’s potential 2016 rivals: Sen. Ted Cruz (Tex.).

Deace said he was unhappy to hear that these voters might be losing confidence in Paul, because he thinks Paul would be a fantastic president.

“I don’t want to see him go down in flames. . . . He’d be the most conservative president we’ve had since Reagan’s first term. Maybe since Coolidge,” Deace said, referring to Calvin Coolidge, the 1920s president whose hands-off approach has made him a conservative icon 80 years after his death. “But he’s not going to get there this way.”