Do you think CNN’s Dana Bash expected a different answer when she asked Senator Joe Lieberman if he’d run as a Republican? Based on her reaction, I’d guess that she expected either a demurral (“I’m not thinking about my next election”) or a denial (“I’m happy to be an Independent/Democrat”). Instead, Lieberman told Bash that “all options are open,” which will only stoke calls from the Left to banish Lieberman from the Democratic caucus and strip his committee assignments:

Independent Sen. Joe Lieberman, a former Democrat who sits with Democratic caucus, said Tuesday that he would not rule out running for re-election in 2012 as a Republican.

Lieberman angered his colleagues in the Democratic caucus this week by threatening to torpedo health care legislation if it contains a government-run public health insurance or an expansion of Medicare.

Lieberman said he wasn’t sure which party, if any, he would represent in his next election.

“I like being an independent, so that’s definitely a possibility,” the Connecticut senator said. “But I’d say all options are open.”

He called running as a Republican “unlikely” but added that he wouldn’t “foreclose any possibility.”

That would be quite a political journey, almost Churchillesque, in a political system that punishes party-jumping. After all, it was just nine years ago that Lieberman represented the Democrats on a national ticket as Al Gore’s running mate. Just switching to an independent is significant, but flipping to the GOP would be almost unprecedented.

And it almost certainly won’t happen. As I explained to a dismayed family member last night after Lieberman indicated he would vote for the ObamaCare bill (without a public option or Medicare expansion), Lieberman is solidly liberal in his domestic politics, even if he’s a hawk on defense. If Lieberman feels uncomfortable with Democrats on their statist expansionism and retreatism on the war, he would feel equally uncomfortable with Republicans on a wider range of issues. The surprise isn’t that he will vote for Reid’s ObamaCare Rump, it’s that he held out against the public plans for this long.

If any Democrat in the Senate is looking to flip, I’d watch either Ben Nelson of Nebraska or even possibly Evan Bayh of Indiana, both of whom have been increasingly critical of their party and both of whom need to distance themselves from it in their upcoming re-election efforts (Nelson in 2012). Those are also long shots, but they’d be more comfortable with GOP policy than Lieberman.