On Wednesday, at a “Millennial Town Hall” at Georgetown University, House Speaker Paul D. Ryan (R-Wis.) fielded a tricky question from a young Republican.

What “reasons for optimism,” the student asked, could Ryan offer to conservative millennials disgusted by the leading GOP presidential candidates?

Ryan’s response was telling. He encouraged young people to ignore the “political personality,” and instead “Look at the ideas. Look at the platform that is being advanced.”

“We win ideas contests,” Ryan declared triumphantly.

With all due respect, Mr. Speaker: No, no you don’t.

The millennial generation is now the largest, most ethnically diverse generation in American history. (Daron Taylor/The Washington Post)

At least not among millennials.

The GOP is poised to permanently lose a generation of voters, and not (only) because of its odious and uncommonly disliked presidential front-runner. New survey data suggest that young people have become increasingly averse to just about every plank in today’s creaky Republican Party platform.

By now it’s well known that young Americans are considerably more liberal than the Republican Party on most social issues, particularly gay rights. The GOP’s own 2012 election “autopsy,” which proposed ways to broaden the party’s base, emphasized that Republicans must change their “tone” on social issues that young people see “as the civil rights issues of our time.”

The latest youth poll from Harvard’s Institute of Politics, though, indicates that LGBT-related policies aren’t the only ones on which young people and Republican traditionalists part ways.

As their rabid support for Bernie Sanders might indicate, young people have also become much more supportive of big government and expanded social welfare programs.

Compared with responses from the past few years, today’s 18- to 29-year-olds are more likely to believe that “basic health insurance is a right for all people,” that “basic necessities, such as food and shelter, are a right that government should provide to those unable to afford them” and that “the government should spend more to reduce poverty.”

More broadly, other surveys have found that young people have more favorable views of socialism than of capitalism — the only age group for which this is true.

Additionally, the Harvard poll found, young people increasingly reject supply-side (a.k.a. “voodoo”) economics, the cornerstone of the Republican fiscal agenda.

Just 35 percent of young people agree that “tax cuts are an effective way to increase growth.” That is 5 percentage points lower than last year, and the lowest share since the poll first asked about this.

On the breakaway issue of the current Republican primary — immigration — young people also could not be more at odds with the GOP base.

For more than two decades, the Pew Research Center has been surveying Americans about whether they believe immigrants “strengthen our country because of their hard work and talents” or “are a burden on our country because they take our jobs, housing and health care.”

The share of millennials saying that immigrants strengthen the country has shot up to 76 percent in recent years, far higher than any other generation and more than twice as high as the share of Republicans who say this.

Young people are also far more likely than other age groups to favor finding a way for undocumented immigrants to remain in the United States legally, and to oppose building a wall on the Mexican border.

On countless other issues — such as whether stricter environmental regulations are worth the cost — young Americans are drifting further from those supposedly winning ideas held by Ryan’s party.

You might be tempted to dismiss some of these findings because young people are almost always more liberal than their elders. Even relative to earlier cohorts of young people, though, today’s youth are shifting leftward.

Some of that shift is compositional: Young people today are more likely to be nonwhite, and nonwhites are more likely to be liberal than their white peers. Demographics tell only part of the story, though. The components of the millennial bloc that are most likely to be conservative have also gotten substantially more liberal, according to a new study from Gary C. Jacobson, a political scientist at the University of California at San Diego.

Jacobson finds that young people who self-identify as Republican are to the left of older Republicans on pretty much every conceivable metric, including whether they approve of President Obama, consume conservative media or believe in man-made climate change.

Millennials are now the largest generation in history, and their voter turnout rates will probably increase with age. Research suggests that political affiliations developed early in life tend to stick. None of this bodes well for the future of the Republican Party, regardless of which candidate it offers up in November.

Unless, that is, it’s willing to change some of its ideas.