Trump hands a key to the millennial vote to Hillary

Hillary Clinton may have found the answer to her persistent problems with millennials: Donald J. Trump.

Clinton, in this week's Bloomberg Politics national survey, enjoys a lead of 3 to 1 among likely voters aged 18 to 29, and more than a 3-to-2 advantage among 30- to 39-year-olds. These millennials still aren't wild about the presumptive Democratic nominee. Her favorable ratings are far below Barack Obama's. But Trump's negatives are stunning: Among 18- to 29-year-olds, 83 percent have an unfavorable view of him.

In 2012, voters under 40, who made up more than a third of the electorate, provided the winning margin for Obama. Trump in this poll, conducted by Ann Selzer, does considerably worse than the 2012 Republican candidate, Mitt Romney, with these voters.

Unless Trump can close this gap significantly, it'll be close to impossible to make up for it with votes from older Americans.

To be sure, whether the millennials turn out in larger numbers as they did for Obama should concern Democrats. Many stayed home in the 2014 congressional elections, costing Democrats a number of seats.

In the Selzer survey, more than three quarters of older Americans say they are likely to vote in November. Only 54 percent of 18- to 29-year-olds and 69 percent of the older millennials say the same. If this holds, it means turnout among the younger millennials would drop sharply from 2012, when they made up 19 percent of the whole electorate. That provides a challenge for the Clinton campaign.

But the concerns are far greater on the Republican side. Political scientists and polling experts find that when young Americans vote the same way in several elections, it often becomes a lifelong pattern. This would be the third presidential election that some millennials opt for the Democratic candidate.

Moreover, their view of the Republican Party is overwhelmingly negative. Democrats do much better.

This is where Vermont Sen. Bernie Sanders could provide substantial help for Clinton in the fall. His favorable ratings are about the the same as the president's with the younger age group, much higher than hers.

Gary Johnson, the Libertarian presidential candidate who favors less government, fewer foreign interventions and less regulation of drugs, has some appeal with young voters. In the horse-race question in the Bloomberg Politics poll, he gets about one in six millennials, twice the support he has from older voters.

One surprise: For all the talk about what a difficult economy it is for younger Americans, these millennials, by decisive margins, say they're better off than they were at the beginning of the Obama administration.