Ryan’s Medicare proposal, as written, has no chance of ever passing, because Democrats still control the Senate and the White House. By contrast, in 2009, the Tea Partyers were reacting to proposals that had a very real chance of passing — and mostly did pass in the end — because they were being debated by leaders from the party that completely controlled the government. The Tea Party’s rage was not just an expression of anger at Obama’s health policies. It was an expression of the broader helplessness voters on the right felt at a moment when it remained unclear whether their representatives in government — i.e., Republicans — had any prayer of acting as a meaningful check on Obama’s entire agenda. The two situations just aren’t all that comparable.As a legislative strategy, remember, the entire GOP effort against ACA was a complete bust. At least the short-term strategy; long-term, over the entire 1945-2010 stretch, Republican opposition succeeded in first delaying comprehensive reform and then ensuring that what was adopted was a market-based, rather than a government-run, approach. But in 2009-2010, Republican opposition did no good at all.
As an election approach, it's harder to conclude what effect if any the GOP outrage strategy had. We can say for sure that Democrats got clobbered in 2010; that most of that was a combination of the economy and exposure (that is, Dems had more vulnerable seats after two straight landslides); that there's fairly good evidence that the actual results were better for Republicans than a pure fundamentals approach would predict; that Members who voted for ACA did several points worse than those who didn't; but that we don't really know how anti-ACA sentiment would have transferred had Barack Obama and the Democrats dropped health care reform entirely. My guess is that it didn't make much of a difference, but that's just a guess.
Anyway, I think Sargent's right: the two situations are different, including the timing to this point.