A Dem party switcher is a future teabagged Republican

Cornyn:

Sen. John Cornyn (R-Texas) said Senate Republicans would "welcome" any Democrats who wish to switch parties and caucus with the GOP.

Cornyn, the head of Senate Republicans' campaign efforts, floated the possibility that the GOP might target Sen. Joe Lieberman (Conn.), an Independent who caucuses with Democrats, or another Democratic senator if Republicans come close to winning a majority but fall short.

On paper, the GOP would have some solid options -- Joe Lieberman is pretty much one of them already, as well as Joe Manchin (assuming he wins), Ben Nelson, maybe even Mary Landrieu.

Here's the thing, though -- the party is no longer in control of its primaries. The teabaggers are running wild, wiping out establishment-backed candidates. Cornyn could protect Nelson or Lieberman or Landrieu as much as Democrats were able to protect Arlen Specter, or Republicans were able to protect Parker Griffith. As Jonathan Singer says:

Republicans couldn't even assure their own incumbents of renomination this year -- just ask Lisa Murkowski, Bob Bennett and Bob Inglis. On top of that, they couldn't get would-have-been Senator Mike Castle through a GOP primary, either, or a score of other party favorites for other offices around the country

Any Democrat switching parties will face a teabagger primary challenge and will lose it. Guaranteed.

The only real drama is whether Olympia Snowe stays with the GOP -- knowing she's doomed in the GOP primar in 2012, whether she switches parties and hope Dems can better protect her, or whether she goes independent early enough that it doesn't look craven like Charlie Crist in Florida this year.