Members of Congress most likely to switch parties

[Del Tachi]

Thad Cochran just for the giggles.

[Oldiesfreak1854]

Almost any center-right/neocon Republican.

Dear Lord no what on God's green Earth are you talking about that is not how the world WORKS

The ideological purity is driving them out of the GOP in droves. 
"Derp neocons and moderates are RINOs and socialists who want to destroy the Constitution!" 
That's the kind of rhetoric that drives folks out of our party.

Prominent 'neocons and moderates' who have been driven out of the party:

• Jim Jeffords (moderate, not a neocon, and this had a lot to do with constituency issues involving dairy farming; the Senate GOP actually had something of a history of bending over backwards for him--this was also during the period of neocon ascendancy within the party anyway)
• Lincoln Chafee (moderate, not a neocon)
• Wendy Davis (I doubt you want to claim her)
• Arlen Specter (moderate, does he count as a neocon? For some reason I never had a firm grasp of his positions on defense and foreign policy)
• Lisa Murkowski sort of but not really.

And a bunch of people who either did not hold political office yet (Patrick Murphy) or did not hold political office any more (Arne Carlson).

I will concede that quite a few 'neocons and moderates' have been driven out of Congress by ideological purity trolls, but that's not really the same thing, pernicious as it is.

The keyword is "and."

'And' is also the word that makes the point so stupid. Next to no remotely prominent neocons, including neocons who are also perceived as moderates, have been driven out of the party.

They haven't been driven out yet, but they will be if the GOP continues on this track.

[World politics is up Schmitt creek]

Almost any center-right/neocon Republican.

Dear Lord no what on God's green Earth are you talking about that is not how the world WORKS

The ideological purity is driving them out of the GOP in droves. 
"Derp neocons and moderates are RINOs and socialists who want to destroy the Constitution!" 
That's the kind of rhetoric that drives folks out of our party.

Prominent 'neocons and moderates' who have been driven out of the party:

• Jim Jeffords (moderate, not a neocon, and this had a lot to do with constituency issues involving dairy farming; the Senate GOP actually had something of a history of bending over backwards for him--this was also during the period of neocon ascendancy within the party anyway)
• Lincoln Chafee (moderate, not a neocon)
• Wendy Davis (I doubt you want to claim her)
• Arlen Specter (moderate, does he count as a neocon? For some reason I never had a firm grasp of his positions on defense and foreign policy)
• Lisa Murkowski sort of but not really.

And a bunch of people who either did not hold political office yet (Patrick Murphy) or did not hold political office any more (Arne Carlson).

I will concede that quite a few 'neocons and moderates' have been driven out of Congress by ideological purity trolls, but that's not really the same thing, pernicious as it is.

The keyword is "and."

'And' is also the word that makes the point so stupid. Next to no remotely prominent neocons, including neocons who are also perceived as moderates, have been driven out of the party.

They haven't been driven out yet, but they will be if the GOP continues on this track.

And what a tragic, tragic loss they would be, I'm sure.

[Badger]

Manchin votes with the Democrats 73% of the time and would gain nothing from changing parties.  I don't understand all this talk about him switching.

According to the New York Times, former Sen. Ben Nighthorse Campbell voted with the Democrats 78% of the time before switching to the Republicans in 1995.

West Virginia does seem like it is moving to the right at the state level much later than the rest of the non-coastal South, so Manchin becoming a Republican could be a benefit in regard to being more in tune with his state.

While Manchin becoming a Republican doesn't seem highly likely, it isn't necessarily out of the question, especially if the GOP wins the Senate after the midterm elections.

Yeah. Campbell's switch was a head scratcher.

Generally, it would seem that a party switch in the Senate would catch people off guard.

I don't think Shelby was so surprising.

True, but there doesn't seem to be an analogue to pre-Republican Shelby in the Senate as of 2014.

How about in the House?

Maybe, just maybe Blue Dog Democrat Dan Lipinski (IL-03). He opposes abortion, opposes same-sex marriage, voted against the final version of Obamacare, is against in-state tuition for undocumented immigrants, and opposes increases in immigration visas. Still, he represents a very Democratic district, and other Blue Dogs who are more conservative than him seem unlikely to switch parties. I suspect that polarization in Congress has reached a level making it unlikely we will see many party identification shifts.

You are dead right about Lipinski's district, which is why he'll never switch, as he'll be in about the same position as Cao or Djou if he ever does.