President Trump gives a thumbs up as he walks to board Marine One on the South Lawn of the White House on Monday. (Jabin Botsford/The Washington Post)

President Trump, a longtime New York City Democrat who campaigned as a populist with little loyalty to the Republican Party, is increasingly choosing to govern as an unwavering conservative.

His first major legislative victory probably will be a $1.5 trillion tax cut that primarily benefits corporations and the wealthy. He is filling the courts with deeply conservative judges who will shape the legal landscape for generations.

And although Trump has struggled to chalk up wins on Capitol Hill, his Cabinet departments are rolling back scores of Obama-era policies on energy, education, the environment and law enforcement. Just this week, Trump cut two of Utah’s national monuments established by Democratic presidents to a fraction of their original size and was preparing to recognize Jerusalem as the capital of Israel, a step long sought by hawks.

At the same time, many of the more populist proposals that Trump championed as a presidential candidate — including promises to curb imports and spur $1 trillion in new spending on infrastructure projects — remain stalled.

“For the past year, he’s done pretty much everything conservatives could have wanted,” said Matt Schlapp, chairman of the American Conservative Union. “In the past, Republican presidents have done conservative things to appeal to the base and then done not-so-conservative things to try to broaden their appeal. They’ve kind of ping-ponged. Trump has really doubled down.”

The pattern has become so pronounced that even some of Trump’s Republican critics acknowledge that — beyond the inflammatory tweetstorms, name-calling and other antics — he is pushing an agenda friendly to their interests and has not aggressively pursued anti-trade moves and other actions that would alarm them.

“As someone who’s been critical of Trump, there’s a lot that his administration is doing that I like,” said Doug Heye, a Republican consultant and former communications director for the Republican National Committee, who said he was particularly pleased with Trump’s judicial picks and other personnel choices.

The conservative tilt is explained in part by Trump’s staff and Cabinet picks, who have been given freer rein by the White House to pursue their own agendas than in past administrations. Those picks — and subsequent policy choices — were heavily influenced by Vice President Pence who unlike Trump has a long history of championing conservative causes.

At a Values Voter Summit in October, radio host and Republican pundit Bill Bennett declared that Trump’s Cabinet was more conservative than that of President Ronald Reagan. Bennett served in that Cabinet as education secretary.

Trump has installed the likes of Environmental Protection Agency Administrator Scott Pruitt, who hails from the oil-and-gas state of Oklahoma. Pruitt used his previous post as the state’s attorney general to sue the EPA over its Clean Power Plan, the principal Obama-era policy aimed at reducing greenhouse-gas emissions. As EPA administrator, Pruitt is leading the charge to repeal the measure.

Other conservative Republicans aggressively pursuing an agenda at their departments include Education Secretary Betsy DeVos, Interior Secretary Ryan Zinke and Attorney General Jeff Sessions.

President Trump, flanked by Speaker of the House Rep. Paul D. Ryan R-Wis.) and Rep. Kevin Brady R-Texas) speaks during a meeting on tax policy in the Cabinet Room of the White House on Nov. 2. (Jabin Botsford/The Washington Post)

Although the investigation of Russian meddling in last year’s election has been the most visible aspect of Sessions’s tenure, he has also been reshaping policies in his department. Those include a new charging and sentencing policy that calls for prosecutors to pursue the most serious charges possible and efforts to strip funding from cities with policies he considers too friendly toward undocumented immigrants.

Trump’s marquee efforts with Congress — the failed attempt to overhaul the Affordable Care Act and the ongoing push to cut taxes — are largely the work of Republican lawmakers cheered on by the president.

“It’s a White House that has largely ceded the ground on legislation to Capitol Hill,” said a GOP consultant close to the White House, who spoke on the condition of anonymity to speak candidly. “So any actions they take are likely to be conservative because of the Republican majorities in the House and the Senate.”

Just after taking office, Trump pulled out of the pending Trans-Pacific Partnership — one of many actions that he promised to take to crack down on what he saw as unfair trade deals. But he has not followed through on threats to label China a currency manipulator or impose tariffs on imported Chinese goods. Nor has Trump made sweeping changes to the North American Free Trade Agreement with Canada and Mexico, though that could still be on the way.

His campaign rallying cry to invest hundreds of millions of dollars in infrastructure projects and to build a southern border wall also remain distant prospects.

Although the likely success on a tax bill is leading some Republicans to be more enthusiastic about Trump, that is hardly a universal view among his GOP critics.

“If the question is whether I’m willing to put up with Donald Trump and the poison he injects into the office for some judges, the answer is no,” said Mac Stipanovich, a Florida-based GOP consultant. “We’re engaged in a war about the truth and whether the truth matters. That’s more important than taxes.”

Bill Kristol, editor of the conservative Weekly Standard, said Trump is doing damage to the conservative cause, regardless of policy victories. He said the fact that both the GOP health-care bill and tax plan poll very badly with the public is a reflection of Trump’s inability to explain conservative policy to the nation, which could have lasting consequences.

“The failure to make an argument has been very damaging,” Kristol said.

More broadly, Kristol said, Trump has done little to advance key principles such as free markets, constitutionalism, limited government and American leadership in the world. “It looks more like he’s doing favors for his buddies in the business world than doing something driven by conservative principles,” Kristol said.

Although Trump did not make energy and the environment a central focus in his campaign, he and his deputies have enacted more concrete policy changes in this arena than almost any other domestic priority.

Some of them have been dramatic, including the president’s decision to pull out of the 2015 Paris climate agreement in June on the grounds that the deal did not advance American interests.

During the first months of the administration, the president signed several bills passed under the Congressional Review Act that abolished some of the last rules issued while Obama was president. He also greenlighted construction of the Keystone XL and Dakota Access pipelines, two controversial projects Obama had effectively halted while in office.

Trump traveled to Utah on Monday to sign proclamations reducing two monuments, Bears Ears and Grand Staircase-Escalante, by 85 percent and 46 percent, respectively. The monuments are just the first of about a dozen protected areas he plans to shrink or alter on the grounds that his predecessors failed to heed concerns raised by local residents or affected industries.

But it is in the regulatory realm that Trump’s election arguably has had the biggest impact. Both Pruitt and Zinke have begun to reverse dozens of Obama-era rules on issues ranging from greenhouse gas emissions to oil and gas drilling.

These include the reversal of rules limiting carbon emissions from existing power plants and methane emissions from oil and gas operations on federal land, as well as restrictions on drilling in national parks and wildlife refuges.

Trump’s efforts to reshape the federal judiciary have also given conservative Republicans something to applaud.

During the campaign, Trump sought to shore up the support of conservative voters by promising to pick Supreme Court justices from a list put together with the help of the Federalist Society and the Heritage Foundation. Justice Neil M. Gorsuch, Trump’s first pick, was among those on the list.

Since approving Gorsuch, the Senate has confirmed nine of Trump’s appellate judges and six district court judges, many with the backing of the same conservative groups.

The courts are, for many Democrats, a vital backstop against many of the changes Trump has tried to bring about, especially by executive order. But some in the party are growing wary of the speed with which the GOP is insisting on confirming conservative judges over the objections of Democrats.

Republican senators broke with long-running practice last week when they scheduled David Stras, a Minnesota Supreme Court justice, for a confirmation hearing to a seat on the U.S. Court of Appeals for the 8th Circuit.

The Senate Judiciary Committee hearing — the first step in the confirmation process — took place despite the fact that Sen. Al Franken (D-Minn.) had not assented to Stras’s nomination as a home-state senator.

With no power to filibuster, Democrats are stuck watching as the GOP approves several relatively young and conservative judges to lifetime appointments on the federal and appellate courts — appointments that could over time dramatically swing the political direction of the federal bench.

Sen. Dianne Feinstein (Calif.), the top Democrat on the Judiciary Committee, recently noted that in Trump's first year in office, the Senate has confirmed more of his circuit court nominees than for any president since Richard Nixon.

Karoun Demirjian contributed to this report.