House Republicans may have voted to pass Rep. Paul Ryan’s budget plan. But Republican leadership is still wary of Rep. Paul Ryan’s budget plan, which includes an overhaul of Medicare and Medicaid:

Last week, House Speaker John Boehner said he was “not wedded” to the Ryan budget that his caucus passed with near unanimity. On Sunday, Rep. Michele Bachmann (R-Minn.) described the Ryan budget that she voted for as an “aspirational document.”

"What I'm saying with that vote is that we have to make decision, we're not saying every single decision in that bill — that aspirational document — will be the final result. What we are saying is that we have a conviction," Bachmann said on "Fox News Sunday."

Given the GOP’s history of entitlement-reform anxiety, this isn’t surprising: When I first started looking into an earlier iteration Rep. Ryan’s budget plan last year, there were only nine GOP cosponsors. Rep. Boehner, along with several other high-profile Republicans, had explicitly distanced himself from the plan, and the loudest Republican criticism of the president’s health care overhaul was that it cut Medicare by $500 billion. (The most recent version of Ryan’s budget—the version that all but four House Republicans voted for—actually included these same cuts.) Rep. Ryan’s staff had at one point been forced to officially clarify that the Ryan plan was not, in fact, the Republican plan, putting out a tersely noting in a statement that, “a Roadmap for America’s Future is a legislative reform proposal offered by Congressman Paul Ryan. It is not the Republican budget.” Now, in its updated form as the Path to Prosperity, it arguably is—at least in the House, where all but four Republicans voted for it. Yet even after voting for the plan, some of them, at least, are still not willing to stand behind it. Meanwhile, Senate Republicans are trying to avoid a vote on the plan entirely.

It’s clear enough why Republican legislators are nervous about the Ryan budget: They worry that the public won't like it, and that Democrats will be able to wield the plan—especially the proposed Medicare overhaul—as a political weapon. But at this point, it doesn’t make much sense to back away from Ryan's proposal. After all, nearly every Republican in the House has already voted for it. Stepping back, and looking uncertain about the plan in the process, isn’t going to help. If Republicans were prepared to vote for it, they ought to have been prepared to defend their votes as well. It’s not clear that that’s the case. When I reported on the Roadmap last year, the Cato Institute’s Michael Tanner told me that the Ryan plan represented a “test” for Republicans, and that, by failing to support it, Republicans (with a few notable exceptions) were failing that test. Roughly a year later, it looks like that’s still true.