The Republicans don't have much of a chance to retake both the House and Senate in 2010. In fact, I don't think they'll retake either.
However, if they do, they will absolutely impeach President Obama -- and it will be for a stupid and frivolous charge. The 100 members of Congress who signed onto Jack Kingston's laughable "czars" bill is a pretty strong indication of what's to come if they gain a majority again.
First, there's no such title as "czar" -- it's shorthand invented by the press. As Cenk Uygur said on his show: it's like the "gate" suffix added to a scandal. It's fun to say but there wasn't an actual "gate" involved in, say, "Travelgate." Second, all presidents have had political and policy advisors in the White House, many of which are unconfirmed by Congress. Just because the press calls them "czars" doesn't mean they're part of a pre-Soviet Russia takeover of the executive branch.
But none of that matters because Glenn Beck is writing material for the congressional Republicans. And just wait until (and if) they have a majority. What we've seen so far will seem quaint compared to the insanity that will come out of a Republican Congress.
At the very least, whatever goals the president might have that you and I would define as liberal or progressive will, in effect, be dead.
Adding... This from an Ezra Klein commenter:
The czar thing also bugged me because it's not an official title. Like if people would have called for the resignation of Tom Delay back in the day because a hammer can't be the Majority Leader. After all, hammers are inanimate objects and it's an affront to American values to have a lifeless tool at such a high office.
And all those whips in Congress! Majority whip. Minority whip. That second one sounds racist, by the way. The Republicans have a minority whip? BAN! BAN! INVESTIGATIONS! HEARINGS! Let's petition Congress to pass a bill banning whips.