President Trump, center, hosts a reception for House and Senate leaders at the White House on Monday, including, from left, Senate Minority Leader Charles E. Schumer (D-N.Y.), House Speaker Paul D. Ryan (R-Wis.) and House Majority Leader Kevin McCarthy (R-Calif.). (Susan Walsh/Associated Press)

As the gavel fell on a critical vote advancing the global trade agenda, Rep. Paul D. Ryan (R-Wis.) pumped his arm, fist-bumped three Republicans and high-fived another.

That was June 2015.

On Monday, President Trump delivered a knockout blow to that agenda. On his first full work day in the Oval Office, Trump formally withdrew the United States from the Trans-Pacific Partnership, a proposed trade pact among a dozen nations that was supposed to have been eased into passage by Ryan’s leadership 19 months ago.

Trump’s move was largely symbolic because Ryan, who was elevated to House speaker a few months after that celebrated vote, had already waved the political white flag on what would have been the world’s largest trade deal.

Throughout 2016, Ryan and Senate Majority Leader Mitch McConnell (R-Ky.) signaled that support for the deal had collapsed in both chambers — in large part because presidential candidates including Trump and Sen. Bernie Sanders (I-Vt.) had successfully portrayed it as a bad pact for American workers.

President Trump, left, talks with House Speaker Paul D. Ryan (R-Wis.), center, and Senate Minority Leader Charles E. Schumer (D-N.Y.) during the reception. (Susan Walsh/Associated Press)

Still, Trump’s actions demonstrate his seriousness about reversing decades of Republican orthodoxy on globalism — a pledge he renewed during Friday’s inaugural address, when he committed to an “America first” agenda.

These actions also show the rocky road that may lie ahead for congressional Republicans on a range of policy issues. On Thursday, Trump and Vice President Pence will join their Republican brethren at an issues retreat in Philadelphia to talk about getting on the same page.

If past is prologue, Trump won’t be asking for the Hill’s help. He’ll be telling his fellow Republicans to get on board or step out of the way. They, in turn, will be figuring out how to stick to their principles while also positioning themselves to play a role in Trump’s success.

The abandonment of the TPP came a short time after Trump’s meeting with business executives, during which he again voiced support for tariffs or a border tax on U.S. companies that build products with cheap foreign labor and ship them to the United States. That policy has already caused friction between the new president and traditional conservatives such as Ryan.

Trump then met with several labor leaders, whose unions had backed Democrat Hillary Clinton in the presidential race to tout his infrastructure agenda. And White House press secretary Sean Spicer told reporters that more executive actions on trade are likely to come later this week.

It’s a stunning reversal for a party that, just two summers ago, continued to support a free-trade agenda.

Ryan, who was chairman of the House Ways and Means Committee at the time, played the lead role in legislation granting special fast-track rules for trade deals for the last months of Barack Obama’s presidency and the first few years of the new administration. The measure won support from 194 Republicans in the House and 48 in the Senate; that’s nearly 80 percent and 90 percent, respectively, of the GOP caucus in each chamber.

It was one of the most important pieces of legislation Ryan ever shepherded into law, as his emotional response on the House floor indicated. It reflected an ideology that has been part of the Republican bedrock since at least the presidency of Ronald Reagan.

Throughout the Obama years, Ryan became the public face of that brand of conservatism, projecting faith in U.S. leadership in open, global markets. “It gives America credibility,” Ryan said during final debate over the 2015 fast-track bill. “And boy, do we need credibility right now.”

That period created a deep rift among Democrats who bitterly fought their president on the issue, particularly those in the Midwest, where the manufacturing sector has been crushed by the movement of jobs overseas and automation in the plants that remain here. In an odd twist, Democrats provided some of the biggest applause to Trump’s formal withdrawal from the trade treaty.

“It’s a pleasant surprise to me. I’m glad that we have a president that’s joining us,” Sen. Debbie Stabenow (D-Mich.), a leader of the opposition to TPP, said Monday evening. She shook her head at the work that McConnell and Ryan put into passing the fast-track legislation intended to lay the groundwork for passing the Pacific trade deal.

“I think their heads must be spinning right now,” Stabenow said.

Ryan’s advisers say the opposite, that the politics of trade had shifted long before Trump won the presidential election — an election in which Clinton, who helped negotiate the initial contours of TPP, reversed course and became an opponent of the deal.

“President Trump is wasting no time acting on his promises,” Ryan said in a statement Monday after the new president issued a string of executive orders. On trade, Ryan noted: “He has followed through on his promise to insist on better trade agreements.”

Republican advisers are quick to say that the bulk of GOP lawmakers still believe in negotiating trade deals. Except now the focus is on smaller, bilateral deals with one nation at a time, as opposed to the more sweeping multilateral deals involving many nations.

Wilbur Ross, a billionaire financier who is Trump’s nominee for Commerce secretary, voiced support for that approach during his confirmation hearing last week.

This reorientation on trade is one of several key policy areas that the Ryan and Trump wings of the party must work through in the months ahead. In his address Friday, Trump returned to his dream of pushing a massive new infrastructure bill for roads, bridges and airports — the kind of largesse that House Republicans have furiously fought in the past.

And all sides within the party are struggling to explain the process and details of how they’re going to replace the Affordable Care Act, which Republicans have promised to repeal.

On Monday evening, Trump met privately with Ryan after a larger, bipartisan huddle at the White House with congressional leaders. The speaker’s aides said the meeting focused on every major policy issue of the moment.

What they didn’t say is what the two men agreed on — and what they didn’t. Which leaves a burning question for Ryan: Will he get on board or step out of the way?

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