MICHAEL BARONE: Still Not Clear Which Party Will Lose The House.

Another way to put it: Republicans got the worst showings of both of their last two nominees, losing even further ground among college-graduate-whites, while failing to duplicate Trump’s gains among non-college-whites.

That pattern was discernible in earlier special elections and makes it easy to see how Democrats could win a House majority. It’s widely attributed to Trump’s combative and provocative style.

There’s something to that, of course, but not everything. The voter shifts from Romney 2012 to Trump 2016 by historic standards were actually small, and the variations of Republican and Democratic percentages in the two-plus decades since 1994 have been historically small, with a steady increase in straight-ticket voting until 2016.

What we’ve also seen in congressional elections since the middle 1990s is a resistance to one-party control. With close presidential elections, only a few voters need defect in the off-year to produce this result and, except for the election just after 9/11, enough voters have done just that.

Former President Bill Clinton faced Republican Houses and Senates for six of his eight years in office. Former President George W. Bush’s Republicans gained seats in 2002, but he faced a Democratic House for two years and a Democratic Senate for three-and-a-half. Former President Barack Obama faced a Republican House for six of eight years and a Republican Senate for two.

You can ascribe the losses of each president’s party as the predictable result of some combination of extremist overreach, legislative fecklessness, personal scandals and suspicion of insiders. But for one reason or another, they keep happening and could again this year, when Republicans could lose their majority in the House and might conceivably, despite their advantage in seats up for re-election, in the Senate too.

But there’s reason to be cautious about predictions. Republicans’ big gains weren’t visible at this point in the 1994 cycle (I wrote the first article predicting they might win a majority, in July of that year), nor were Democrats’ big gains in 2006 or Republicans’ sweep of Senate seats in 2014.

Nor are polls this far out always a reliable guide to November.

Nope. Just pick a candidate you like who needs help and help them.