Sen. Rand Paul (R) officially announced his campaign for president in his home state of Kentucky. Here are his full remarks. (AP)

Sen. Rand Paul of Kentucky launched his bid for the White House on Tuesday as the most distinctive voice in the Republican Party’s presidential field. The competition ahead will answer whether his candidacy can remake his party or will be undone by the orthodoxies he seeks to upend.

Paul’s announcement speech was a reminder of why he often has been called the most interesting politician in the country, with a libertarian message that seemed to sweep across the ideological spectrum and that challenged the establishment of both parties.

But the address underscored as well the challenge Paul faces in trying to take the many pieces of his vision and convert them into a cohesive whole capable of attracting a winning coalition. On domestic and especially foreign policy, he will find himself under attack from his Republican rivals.

In his speech, the first-term senator wore many hats. He was part tea party activist, with a revival of the strong anti-government message that propelled him to victory in the 2010 Senate primary against the Kentucky GOP establishment led by Mitch McConnell, now the Senate majority leader.

“I have a message, a message that is loud and clear and does not mince words,” Paul thundered as he took the stage before an enthusiastic audience of supporters. “We are here to take our country back.”

He painted his candidacy in vivid symbolism. “We need to go boldly forth,” he said, “under the banner of liberty that clutches the Constitution in one hand and the Bill of Rights in the other.”

He decried spending and deficits and the power of lobbyists and insiders, with a sign on the lectern that read, “Defeat the Washington Machine.” He said Washington is “horribly broken” and called for a constitutional amendment to balance the budget and for term limits for members of Congress.

But if he was a small-government tea party reformer, he was also channeling Jack Kemp, the late Buffalo Republican congressman and housing secretary who preached outreach to minorities and aid and assistance to inner cities and rarely worried about deficits.

Paul has elements of Kempian philosophy in his message, including economic freedom zones that he said could help revive Detroit just as Kemp said his enterprise zones could revive the Bronx. Paul also advocated criminal justice reforms that he hopes could attract the votes of African Americans and other minorities who have spurned the Republican Party.

Lest he be mistaken for a believer in the power of the central government, however, he cast his philosophy as a contrast to the policies of the Democrats. “Liberal policies,” he said, “have failed our inner cities. . . . It’s time for a new way, a way predicated on justice, opportunity and freedom.”

Sen. Rand Paul, (R-Ky.), who announced he's running for president in 2016, is known for his belief in limited government. Here his take on the Affordable Care Act, the Constitution and more, in his own words. (Julie Percha/The Washington Post)

On civil liberties, Paul positioned himself to the left of President Obama, railing against what he called the “unconstitutional surveillance” of the American people by the NSA. He called warrantless searches of phones and computer records “un-American” and a threat to civil liberties.

Holding up a smartphone, he said, “I say the phone records of law-abiding citizens are none of their damn business.” As president, he said, he would end the surveillance program “on Day One.”

It was in the area of foreign policy that Paul seemed to be working hardest to balance his past philosophy and statements and his current and future ambitions. With some Republicans fearful that he espouses an anti-interventionist philosophy, he offered strong rhetoric against America’s enemies.

Again he sought to use Obama as a foil, declaring that America cannot defend itself adequately unless it can name the enemy. “The enemy is radical Islam,” he said. “You can’t get around it.” He called for a national defense “robust enough to defend against all attack, modern enough to deter all enemies, and nimble enough to defend our vital interests.”

He repeatedly used the word “defend” to describe his national security policy. What he did not say, as Obama and many of his GOP rivals have said, was that his goal is to destroy Islamic State militants. He said the goal of any U.S. foreign policy should be “stability, not chaos.”

For those on the right who he suggested are too often bent on military intervention and the consequences that come with it, he had only criticism. He invoked President Ronald Reagan by saying he would envision a foreign policy of peace through strength rather than military unilateralism.

“Conservatives should not succumb, though, to the notion that a government inept at home will somehow succeed in building nations abroad,” he said.

Far from any nation building, Paul said he would deny foreign aid to countries where mobs burn the American flag. “I say it must end,” he declared. “I say not one penny more to these haters of America.”

He was perhaps most careful and least clear on the current controversy of the Obama presidency: negotiations with Iran to prevent it from developing a nuclear weapon. On this issue, his rivals appear united in their opposition to what Obama is doing. Paul staked out a position modestly endorsing negotiations while reserving space to oppose any agreement.

He argued that Congress must approve any eventual deal. He said he would oppose any agreement “that does not end Iran’s nuclear ambitions.” But as someone who has warned against making the military option against Iran the only option, he also said negotiations are “not inherently bad.”

He tried to distance himself from the administration’s posture by saying the difference between him and Obama is that the president “seems to think you can negotiate from a position of weakness.” But he avoided siding with the most militant of hawks in his party, by saying, “Our goal always should be and always is peace, not war.”

As he begins his campaign, Paul is well positioned in this sense. No one else has any more potential to build strong support in the first three states — Iowa, New Hampshire and South Carolina. His father, former congressman Ron Paul, was a force in both Iowa and New Hampshire four years ago, and the senator hopes to use that base as a foundation. A quick start would be a powerful boost to his candidacy.

But those contests are months into the future. As the competition heats up this year, many of his rivals will seek his undoing, calling into question the specifics of his vision, the consistency of his convictions and his readiness to be commander in chief. That’s when he will have to prove it is not enough just to be interesting.