If Pat Toomey of Pennsylvania wins, for instance, it will tell Republicans that their own brand hasn't been hurt too badly by [Donald] Trump's negatives.

The Democrats pulled out one of their most powerful surrogates - and no, it wasn't President [Barack] Obama. Beyoncé showed up at a GOTV rally in Cleveland, joining her husband, Jay Z, and Hillary Clinton.

[Donald Trump ] would make history in so many ways because he is a candidate who eschewed the traditional arts of political campaigns, including field organization, traditional advertising, debate preparation and policy knowledge.

After months and months at the top of the polls, there is a real possibility that Donald Trump could be the nominee.

[Donald] Trump has said he will accept the results of the election - if he wins. And he has said the only way he can lose the election is if it's stolen from him. Weeks before any votes were cast, he was predicting widespread voter fraud. So if he loses, what does he do?

The winner's margin of victory also matters. If it's a squeaker, that will make the lessons learned for both parties much murkier.

If [Donald] Trump drags down a bunch of Senate Republicans, the post-election GOP assessment will be much more pessimistic.