CLEVELAND — House Speaker Paul D. Ryan spent a career honing an image as one of Washington's most serious, likable and wonkish Republicans.

At a recent fundraising dinner, he dazzled finance industry leaders by sparring for more than an hour over the intricacies of monetary policy.

He used his leadership position this year to turn the House into an incubator for GOP policies on poverty and taxes. During the mud-slinging Republican primary, he implored presidential candidates to "raise our gaze."

Yet on Tuesday night, Ryan found himself presiding over a presidential convention that nominated a Republican nominee who could not be more different in style and substance from the 46-year old Wisconsin congressman.

As Ryan conceded just days ago, Donald Trump is "not my kind of conservative." He previously called Trump's attack on an American-born judge of Mexican descent the "textbook definition of racism."

And only after a very public hand-wringing did the 2012 vice presidential nominee reluctantly agree to endorse Trump with a logic that only a debate champ might appreciate: he called it a "binary choice" of either supporting Trump despite misgivings, or helping Democrat Hillary Clinton.

In a convention speech Tuesday night, Ryan tried again to bring his party together, focusing largely on the risk of electing Clinton rather than the promise of Trump, whom he scarcely mentioned.

"Democracy is a series of choices, he said. "We Republicans have made ours. Have we had our arguments this year? Sure we have."

But he characterized the internal disputes as a promising "sign of life" and energy inside the party and said the time had come to unify.

"This year of surprises and dramatic turns can end in the finest possible way — when America elects a conservative governing majority," he told delegates. "So what do you that say we unite this party, at this crucial moment when unity is everything?"

Ryan still faces an uphill battle for the rest of the week: Can he unify a fractured Republican convention boycotted by most of the party's biggest names and inject some of his own traditional GOP policy prescriptions into an inexperienced, unpredictable and often hostile presidential campaign whose positions sometimes contradict long-standing Republican ideology?

The task is a risky one for Ryan. While he may succeed in holding the party together, helping to elevate Trump's White House bid, it could come at the expense of the core GOP principles that have been Ryan's life's work.

At stake is not only Ryan's brand as the keeper of conservative ideology of Washington, but also the future of the Republican Party. His differences with Trump over trade, immigration and the treatment of Muslims and other minorities are stark.

"The party's at a real inflection moment and the outcome is not clear," said David Winston, a Republican pollster and strategist aligned with House Republicans. "One of the things that Ryan is trying to do is at least have something — some clear policy direction here — that Republicans can use that's a structure for maintaining the Republican coalition — at least at the congressional level."

Foremost for Ryan is protecting his Republican majority in Congress, including the biggest House majority in generations, as lawmakers face voters this fall in the Trump era.

To that end, the speaker has been working feverishly to raise funds — which is why he appeared before the financial industry donors recently — and provide lawmakers with an alternative platform to run their campaigns.

Even before Trump became the nominee, the speaker turned the House majority into a think tank on Capitol Hill, doing what he does best — churning out a GOP agenda, "Better Way," that offers policies on taxes, health care, poverty and other issues lawmakers can discuss with voters back home.

The hope is the platform gives Republicans something to talk about — instead of having to react to the latest outburst or Tweet-storm from Trump.

"His instincts are right — always bring it back to ideas, always bring it back to providing people a vision for how to make America better," said Kevin Madden, a former aide to Romney and previous Speaker John A. Boehner, R-Ohio.

"He may not be successful in having the presidential nominee stick to that playbook, but he can have impact on the overall environment Republicans are going to run in and putting ideas front and center."

On Tuesday, Ryan showcased his ideas. "We offer a better way for America, with ideas that actually work. A reformed tax code that rewards free enterprise, instead of just enterprising lobbyists. A reformed health care system that operates by free choice, instead of by force, and doesn't leave you answering to cold, clueless bureaucrats. A commitment ... to building a 21st-century military — and to giving our veterans the care they were promised, the care that they have earned."

The speaker is popular among rank-and-file lawmakers who appreciate his willingness to take center stage at a time when many of them prefer to avoid tough questions.

But as the convention opened Monday, Ryan notably skipped presiding over the convention's first day when a raucous floor flight erupted in opposition to Trump's nomination. Ryan's schedule had been set earlier, aides said, but his absence enabled him to avoid taking sides in the messy showdown.

"It's not fun," said Michael Steel, a former top aide to Boehner and Trump rival Jeb Bush.

"This was the year that a reform-minded conservative presidential nominee, against an incredibly flawed Democratic nominee, had a chance of winning the White House," Steel said, adding the speaker's job is to help his fellow Republicans win races, "regardless who is at the top of the ticket.

"The speaker and his staff have helped adroitly with that, under the circumstances."