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Editor’s note: Romney has Ryan as his running mate.

Conservative anxiety has stalked Mitt Romney since the outset of his presidential campaign, expressing itself in a series of hopes that a nominee who was not Romney might win, and then, after his nomination became inevitable, as endless caterwauling for Romney himself to act less … Romney-like. Romney’s vice-presidential selection has begun to serve as a stand-in for these demands, and as recently as a week ago, they split between calls for him to pick Paul Ryan and calls for Marco Rubio.

But since then, Romney’s position has steadily eroded, intensifying the conservative panic. And a report by National Review’s Robert Costa that Romney was giving Ryan strong consideration focused all the attention on the dreamy House Budget Committee chairman and unofficial party leader. Suddenly Ryan’s potential nomination has become the sole locus of the conservative movement’s longings.

The reason Ryan had earlier been deemed unlikely was that Romney intended to run a campaign focused entirely on the economy. His reasoning was sound enough. Romney’s status as the challenger during an economic crisis with mass unemployment was a gigantic asset, but it was (aside from his growing Superpac advantage) his only asset. America still hated the Republican Party, hated its Congressional wing, and bitterly opposed the fiscal priorities it championed. Romney understood that he needed to bring together nearly every voter dispirited with the status quo, and not only those also eager to join a crusade to smash the welfare state.

Conservatives had been itching to enlist Romney more openly in just such a crusade, out of the same overweening ideological confidence that drove them to enlist the Republican Congress. And Romney’s campaign plan has begun to look increasingly shaky. Obama has successfully defined him as a self-interested agent of his economic class. Polls have shown that Romney’s perceived advantage in handling the economy, his only advantage, has dwindled to little or nothing. (The latest Fox News poll has Romney’s advantage on the economy dropping from 7 points to 3; in CNN’s poll, just 29 percent agreed that the economy will improve only if Romney wins — this is his entire campaign premise! — while 31 percent said it would improve only if Obama wins.)

The oft-repeated conservative argument for Ryan is that Romney has already endorsed the Ryan plan closely enough to incur its liabilities, so he might as well pick the politician best equipped to defend it. There’s certainly something to this. Ryan gets too little credit for his political skills. He has won consistently in a moderate district. He has managed to build a reputation among the national press corps as a thoughtful, compromise-friendly moderate while hewing to the right wing of his party. The major argument of my profile of Ryan from last spring is that his public persona is a giant scam; but pulling off a scam like that is the mark of a skillful pol.

On the other hand, Ryan’s capacity for national-level wholesale politics has yet to be proven. He has masterfully played the Washington press corps, but it remains largely an inside game. Most Americans have not formed an opinion about him. He has a long record of radical votes and is the functional leader of a wildly unpopular Congressional wing. The one real electoral test of his plan’s political tolerability came in a special election in a Republican district in upstate New York in 2011, in which an underdog Democrat swept to victory by relentlessly pounding Ryan’s plan, and especially its provision to privatize Medicare.

At this point, joining Ryan to the ticket would be a huge gamble. Romney would be tapping into Ryan’s immense political talent, but giving up on his win-by-default strategy that has taken a beating but might look good again if, say, some international disaster craters the recovery between now and November. In any case, the conservative drumbeat for Ryan has grown so overwhelming that it’s no longer even clear that Romney could turn Ryan down for an Incredibly Boring White Guy, even if he wants to. The Republican Party belongs to Ryan.