It's primary day in Ohio, Indiana and North Carolina. Here's what the WashPost's Chris Cillizza says to watch next-door:

1. Ohio 'Mo or No: Ohio Lt. Gov. Lee Fisher has been one of the biggest disappointments of this election so far for Senate Democrats. He has struggled badly to distance himself from badly underfunded Secretary of State Jennifer Brunner in the primary and has woefully underperformed in his own fundraising as well.

But, a Quinnipiac poll released Monday showed Fisher with a 43 percent to 23 percent edge over Brunner, suggesting that the lieutenant governor was headed to a relatively pedestrian win today.

A convincing victory -- along the margins that the Q poll suggests -- could give Fisher a bit of badly-needed momentum as he moves into the general election against former Rep. Rob Portman (R).

Despite Fisher's struggles, polling puts him even or slightly ahead of Portman -- a trend line that has to be encouraging for Democrats. Fisher needs to show that he has fixed the problems that plagued his campaign for much of 2009 and the best way to do that is to put a big number on the board tonight.

And here's Jeff Zeleny in the NYT:

The three states share a common thread: President Obama pulled them into the Democratic column in 2008. That result elevated Indiana and North Carolina into the political battlegrounds that Ohio has long been. The Democratic success has given Republicans an extra measure of incentive for strong performances as they try to rebuild and regroup before 2012.