With Clinton Near Clinching, a Lookahead to the Main Event (POLL)

— -- With Hillary Clinton poised to claim the Democratic nomination this evening, basic questions loom over her anticipated general election contest against Donald Trump. Will Bernie Sanders supporters line up behind her? And how will she stack up against Trump on key issues and personal attributes as voters make their choices in the months ahead?

Our most recent ABC News/Washington Post poll helps sets the scene, supported by exit poll results from the primary season and past years. A summary of central considerations follows.

Sanders voters

One important question revolves around Sanders’ candidacy -– in short, when and how it ends, and the extent to which the party coalesces around Clinton, should she emerge, as expected, as the party’s nominee.

Twenty percent of Sanders’ supporters in ABC/Post polling say they’d vote for Trump over Clinton -– a result that may reflect the unsettled nature of the Democratic race rather than durable support for Trump in this group. Consider the similarities to this point in 2008, when 24 percent of Clinton supporters said they’d vote for John McCain over Barack Obama. It didn’t happen; her voters got over their loss and ultimately backed the party’s nominee.

Clinton, of course, wholly supported Obama after losing the nomination to him eight years ago -– albeit after first threatening a convention fight, as Sanders is doing now. While politicians cannot trade voters like baseball cards, the manner in which Sanders responds to a Clinton nomination may help determine whether some of his supporters accept her, look seriously at Trump – or just sit it out. Sanders’ current intention to carry on raises the question of whether his backers will take the time to warm to Clinton – or instead harden their opposition to her.

Young voters

This especially holds for voters under age 30. They’ve been huge for Sanders; he’s won them by 71-28 percent against Clinton in primaries for which we have exit poll results. And they may have an especially hard time getting over his likely defeat at Clinton’s hands.

We say so because under-30s moved from 64-25 percent Clinton-Trump in March to 45-42 percent in May, suggesting resentment as Clinton’s moved ahead of their true love, Sanders. She needs them back: Under-30s were huge for Obama in 2008 (a record 66-32 percent) and 2012 (60-37 percent) alike, an essential element of his winning coalition in both elections.

That said, under-30s are not always broadly Democratic voters. John Kerry won them by a much closer 54-45 percent in 2004, and they split essentially evenly between Al Gore and George W. Bush, 48-46 percent, in 2000. Kerry and Gore lost, of course, suggesting that if under-30s don’t swing back to Clinton, she’s got a problem.

The status quo

A further challenge for Clinton is that she’s a status quo candidate in a year with considerable anti-status quo sentiment, as demonstrated by Trump and Sanders. The slow economic recovery has left many aside; underemployment, long-term joblessness, decades of declining real income for the two-thirds of adults who lack a college degree and soaring loan debt for recent graduates all have sown the seeds of discontent. Presenting herself as a change agent – Obama’s route in 2008, Bill Clinton’s in 1992 – is no easy task for Clinton after her decades on the scene. Then again, Obama’s bare majority approval could make the status quo more attractive to some voters, boosting Clinton in the process.

Minority voters and college-educated white women

That said, Clinton has two aces in the hole: Her support among minority voters and among college-educated white women.

Clinton holds a 69-21 percent advantage over Trump among racial and ethnic minorities who are registered to vote, including 84-11 percent among blacks and 69-21 percent among Hispanics. (These combine March/May results for adequate sample sizes.) She’d like to do better (Obama won nonwhites by 80-19 percent in 2012) but it’s still a key advantage in a growing group. Nonwhites have advanced as a share of the electorate from 10 percent of voters in 1976 to 28 percent in 2012. They’re the reason Obama was able to lose whites by 20 points in 2012 and still score an electoral college landslide.

For Clinton to lose, nonwhites’ share of the electorate will have to decline, something that’s happened just once in the 36-year history of exit polls; she’ll have to do unusually poorly among them; or she’ll have to lose whites by significantly more than a 20-point margin, something that hasn’t happened since Ronald Reagan hammered Walter Mondale in 1984. But it could occur in 2016: Trump leads Clinton by 24 points among whites in our latest data.

That reflects Trump’s large advantages among white women who lack a college degree and white men overall – especially less-educated white men, a group Mitt Romney won by 31 points but in which Trump currently leads by a breathtaking 62 points, 76-14 percent.

Clinton’s hoped-for bulwark is college-educated white women. Obama lost this group by 6 points in 2012; Clinton leads among them by 24 points, 57-33 percent, in our latest data. (Indeed she leads among women overall by 14 points, while Trump leads among men by 22 – double the typical gender gap of recent elections.)

Minority voters and college-educated white women accounted for a combined total of 45 percent of all voters in 2012. Clinton’s current lead in this aggregated group is 65-25 percent, compared with Obama’s 66-32 percent in 2012.

Popularity

These equations make clear the underlying truth of most elections – that they’re less about changing minds and more about motivating your supporters to turn out, and/or demotivating the other candidate’s voters. In this election, motivation may be a problem for both likely candidates, given their record levels of unpopularity.

A remarkable 57 percent of registered voters see Clinton unfavorably overall, and it’s identical for Trump. (Clinton’s advantage is among non-registereds - helpful to her only if they sign up.) They’re the two most unpopular likely major-party nominees in ABC/Post polls dating to 1984.

While unpopularity endangers both candidates, the bigger risk may be Clinton’s. That’s because – all else equal – low-turnout elections usually favor GOP candidates, since Republicans are more habitual voters. (Consider, for example, midterm rather than presidential elections.)

Attributes and issues

Clinton, though, has considerable ammunition with which to try to motivate her supporters, and perhaps more effectively, demotivate voters from backing Trump. These include advantages on key attributes and issues, several of which she stressed in her sharp criticism of Trump’s qualifications in a major speech last week.

Consider that 58 percent of all Americans, and 56 percent of registered voters, see Trump as unqualified to be president. Far fewer see Clinton as unqualified, 36 and 40 percent, respectively. Further, Republicans themselves divide on whether Trump represents the party’s core values.

Among registered voters, moreover, Clinton leads by 39 points (65-26 percent) on experience, 26 points (59-33 percent) on having the right personality and temperament for the job and 23 points (57-34 percent) on having more realistic policies. They’re essentially even on five other personal attributes, but Trump leads only on one, who’d more to bring needed change, by 14 points (53-39 percent).

On issues, Clinton leads especially widely, by 35 points, in trust to handle issues of special concern to women, but also by 17 points in trust to handle an international crisis, 15 points on international relations generally and 14 points in trust to assist the middle class. Again they’re fairly close on five others, but leaving only one with a substantial Trump advantage, 13 points in trust to handle taxes.

Trump made hay in the primaries on the two issues he rode to prominence last summer – banning Muslim visitors and deporting undocumented immigrants. We’ve shown that these, along with a sense that whites are losing out because of race-based preferences, are a prime factor in his support within the GOP, fueled in large part by desire for traditional authority. (The other factor is outsider appeal/populism, fueled by economic discontent.) It’s more of a question how well these may work in a general election, because they’re so partisan in nature. Seven in 10 Trump supporters favor banning Muslims and as many back deporting undocumented immigrants; three-quarters of Clinton supporters oppose both.

Another issue, though, is more of an aisle-crosser, and it’s one on which Trump has an advantage – opposition to free trade. Sixty-seven percent of Trump’s voters think trade agreements kill U.S. jobs; in this case, though, nearly half of Clinton’s supporters, 46 percent feel the same. Trade is an issue on which Trump may have the opportunity to keep Clinton on defense, while she aims at his weaknesses in qualifications, experience and temperament.

Third party

A final wildcard is the potential influence of one – or more – credible third-party candidates. Forty-four percent of registered voters in ABC/Post data say they’re dissatisfied with a Clinton-Trump choice and would like to see a third-party candidate run. Two-thirds of Sanders supporters say so, as do 56 percent of Republicans and GOP-leaning independents who wanted someone other than Trump as their party’s nominee.

That said, desiring a third-party choice is different from actually backing a third-party candidate. In the latest available data, a Quinnipiac poll last week, the Libertarian Party candidate Gary Johnson had 5 percent support and the Green Party candidate Jill Stein had 3 percent. They did not change the basic contours of a Clinton-Trump contest.

That’s customarily the case; traditional party allegiance is such that third-party or independent candidates historically have not fared particularly well (best in the past century was Ross Perot’s 19 percent in 1992.) Nor is it at all clear that Perot’s candidacy (or, for that matter, Ralph Nader’s and Patrick Buchanan’s in 2000) affected the election outcome.

All these factors will play out in the months ahead, as voters consider and come to their choices – whether to vote, and if so, for whom. That’s why, at this stage, current vote preferences matter less, while underlying values, partisan preferences, issue positions, candidate assessments and views of the nation’s prospects matter more – all topics on which the main event is just now beginning.