The puzzling scenarios are courtesy of Dave Helling at Prime Buzz:

So if you’re Roy Blunt, or Sam Graves, or especially Jo Ann Emerson, the prospect of a 2010 Senate race might seem a good alternative to a nasty 2012 House race against another incumbent.

This was written before Jo Ann left. But I can’t quite figure out a map that would pair Jo Ann Emerson with another incumbent. If Jo Ann Emerson and Russ Carnahan were in the same district, it would be pretty tough. That’s really the only plausible “incumbent v. incumbent” scenario unless the judge-drawn redistricting plan puts Emerson in a district with Luetkemeyer.

Basically, I am not Rand McNally, but I’m pretty sure that Emerson won’t get paired up. Republicans drawing an 8 district plan would rather create a 5-3 delegation (as opposed to the 5-4 one we have now). Unless the federal judge who draws a compromise plan has some idea that I don’t have, she’ll have her own district. (I’m only mentioning judges as that would be the most likely conclusion unless one party has the Governor’s mansion and both chambers in 2011)

Also, Roy Blunt’s not particularly likely to be drawn in a district with another member, especially since the 7th has shrunk every ten years due to population growth. With a drop from 9 to 8, the 7th should probably hold even, size-wise.

Redistricting may be quirky for Sam Graves, I’ll admit that (although the suburbs he could get wouldn’t be too hostile to him in November). But, I’m not seeing any way that you can draw Springfield and Miller County in the same district, Cape and Miller County, Cape and South St. Louis, or anything else like that. Maybe I just didn’t take enough creative drawing courses here.

Also, I wouldn’t quite call Claire McCaskill “increasingly popular” yet. But it’s plausible that her 2012 opponent won’t be a sitting Congressman. For all we know, Claire McCaskill will face Matt Blunt (who’ll be making that comeback that some swear is due to happen).