Let us travel now to Michigan, where the open D seat is rated either a Toss Up or Leans D by the respectable outfits — but where there’s some amount of turmoil in the D camp. Politico reports:

Democratic Rep. Gary Peters, who is locked in a tight battle with Republican Terri Lynn Land, has replaced his campaign manager.

Paul Tencher, who ran now-Sen. Joe Donnelly’s winning campaign for the Democrats in Indiana last cycle, will take over as the head of Peters’s campaign operation. Tencher will replace Julie Petrick, who is stepping aside for personal reasons, Peters said in a statement.

Those personal reasons might have something to do with what Politico later describes as “a fairly lackluster few months” for the Peters campaign. Land has had her campaign braced by a couple of timely anti-♡bamaCare!!! ads being run by those dastardly Koch Brothers.

The GOP got a boost here in Colorado last week when Cory Gardner dropped into the Senate race while the hapless Ken Buck dropped out. But Mississippi Democrats got a boost of their own. The Hill has that story:

[Democrats'] shining hope is that Republicans have been in that position before and squandered their chances with poor candidates and intra-party fights.

Developments like Friday’s in Mississippi, where Democrats recruited former Rep. Travis Childers into the contest, are exactly what Republicans don’t need. The fact that the one-term congressman was wooed into a long-shot contest shows Republicans still haven’t solved their primary problem.

Childers is Democrats’ insurance policy, the same way Joe Donnelly was in Indiana and even Chris Coons was, to a lesser degree, in Delaware in 2010 — and now both are in the Senate. But in the heart of Dixie, Democrats can’t win without a pro-gun, anti-abortion, conservative Democrat like Childers who voted against the Affordable Care Act.

I’m not sure anyone had Mississippi in play, but Childers could certainly put it there.

The Democrats are playing defense, so almost any widening of the playing field is bound to hurt them. Mississippi would be an exception to that rule.