The first impossible thing is that Hillary Clinton might stop being the undisputed frontrunner for the Democratic nomination.
There have been two good reasons for believing this to be impossible. One is that even in the swirl of the email controversy, a very large majority of self-identified Democrats continue to have positive feelings about Clinton. That includes the 25 percent or so nationally and the 40 or so percent in New Hampshire who say they’d vote for Bernie Sanders right now.
That shows that one Democratic constituency — the Birkenstock Belt — is willing to consider an alternative. What would happen if another — black Democrats — should prove willing to do so as well?
The answer: disaster for the Clinton campaign. As fivethirtyeight.com analysts have pointed out, even if Clinton loses Iowa and New Hampshire, the next big set of contests come in Southern states, where blacks make up nearly half or more of Democratic primary voters. And black voters tend to coalesce, in primaries as well in November, for one candidate.
That’s a rational response for people who are self-conscious members of a persecuted and discriminated-against minority. In the past, black Democrats have been nearly unanimous for one candidate even over another who has strong claims on their support — e.g., Robert Kennedy over Hubert Humphrey in 1968 and Barack Obama over Hillary Clinton 40 years later.
…The second impossible thing that could happen is a vast expansion of the Republican primary electorate — and general election turnout. Sparked, at least initially, but not necessarily permanently, by Donald Trump.
The New York Times reported last week that other Republican candidates’ strategists discount Trump’s current poll leads on the grounds that the polls “rely on feedback from many Republicans who are unlikely to vote” because they aren’t registered Republicans or haven’t voted in past primaries.
It’s true that past Republican turnout has been low. In 2008, 37 million Americans voted in Democratic primaries and caucuses and only 21 million voted in Republican contests. Hillary Clinton, while losing the nomination, got almost as many votes as the three leading Republicans put together.
Similarly, many analysts blame Mitt Romney’s 2012 loss on conservatives staying home. Barack Obama got 3.5 million fewer votes in 2012 than in 2008. Usually incumbents who drop that far lose. But Romney got only 1 million more votes than John McCain in 2008.
Source: Two Impossible Things That Could Happen in 2016 – Michael Barone – Page full