Stephen Colbert had a field day with Newt Gingrich's nutty wavering over his own criticism of the GOP proposal to end Medicare as we now know it by handing out vouchers to seniors to buy health insurance instead of covering most of the cost with a government insurance program.

It's hardly surprising that Newt isn't embracing the GOP plan: It's proving to be wildly unpopular. Here's what former Bush administration speechwriter David Frum says about the Republican proposal:

[T]he American public will not accept this kind of reform and will smash any politician who tries to force it upon them. There are ways to reduce the fiscal burden of Medicare, but telling seniors to buy their own damn healthcare is not going to be one of them. I wish it were somebody other than the Kenyan-anticolonialism-sharia law candidate making that argument, but it’s an important argument from any source.

Now Talking Points Memo notes that Newt might have apologized to Congressman Paul Ryan for what he said about the GOP's Medicare plan, but he evidently still doesn't support the plan to ask seniors to buy their own health insurance with some help from the government:

Newt Gingrich has been extremely contrite lately, reaching out to conservative commentators, bloggers, and lawmakers in recent days to personally apologize for slamming the GOP budget as "right wing social engineering." Perhaps lost in the overwhelming appearance of a full walk back is that Gingrich hasn't really walked back anything.

"If I were re-wording it, I would have said it slightly different," he told Wisconsin TV station WXOW on Wednesday. "The intent was the same, but I'm happy to continue to evolve."

His words echoed comments he made on Tuesday to conservative bloggers, in which he expressed vague regret for his phrasing on Meet The Press but little more.

"I used language that was too strong, although the underlying principle I think is right," he said.

Gingrich has made repeatedly clear both in his own words and through his spokesman Rick Tyler in recent days that he still does not support Ryan's Medicare plan. Even his assertion that he would have voted for the House GOP budget includes the caveat that he would have made changing the Medicare portion his next priority.

Jon Stewart had his fair share of fun with Newt last night as well.