U.S. House Budget Committee Chairman Rep. Paul Ryan (R-WI) speaks...

U.S. House Budget Committee Chairman Rep. Paul Ryan (R-WI) speaks as Rep. Cathy McMorris Rodgers, right, and Rep. Martha Roby listen during a news conference after a House Republican Conference meeting at the Capitol Hill Club in Washington, DC. (July 18, 2012) Credit: Getty Images

The Wall Street Journal editorial page has joined the growing movement of influential conservatives uniting behind hero wonk Paul Ryan for vice president. "The larger strategic point," they counsel, "is that Mr. Romney's best chance for victory is to make this a big election over big issues." And Ryan is Mr. Big Issues.

But the smaller, more Machiavellian point is that Ryan, the House member from Wisconsin, is Romney's best chance to diffuse the blame if he loses this election. If Romney chooses the proverbial "incredibly boring white guy" and then goes down in November, conservatives will place the blame squarely on Romney's shoulders: He was a flip-flopping, Massachusetts moderate with a cautious campaign and a car garage. The narrative, in fact, is already set. In July, the Wall Street Journal editorial page accused Romney of "slowly squandering an historic opportunity." They would simply have to change "squandering" to "squandered." And Romney knows it.

But if Romney chooses Ryan -- if he makes this the "big election over big issues" that the Wall Street Journal editorial page wants -- then his loss will be their loss as well. He'll still be blamed, of course. But the fact will remain that he took conservative counsel, adopted conservative ideas, named a conservative hero as his vice president, ran on the Ryan budget, and lost to a liberal. The right will not be able to pretend they weren't on the ticket. They will have chosen the ticket. The right will not be able to say Romney ran a cautious campaign. They will have cranked his campaign's strategy up to 11.

What's less clear is what conservatives get out of the deal, save the opportunity to see Ryan debate Joe Biden. If Ryan is named to the ticket and the ticket loses, the loss will discredit the Ryan budget, and empower those in the Republican Party who want to pivot back to the center. Whereas conservatives have some chance of winning the intraparty argument if a ticket of Romney and Sen. Rob Portman of Ohio loses -- "we shouldn't have nominated the insincere moderate," they'll say -- they have little chance of arguing that the Republican Party simply didn't run hard enough on the Ryan budget if Romney-Ryan loses.

Nor is Ryan suffering from a dearth of influence right now. He's proving perfectly able to set the agenda of the Republican Party -- and of most every Republican presidential contender, including Romney -- from his perch as chairman of the House Budget Committee. Perhaps he would be slightly more effective at leading the Republican Party and setting the terms of the national debate as president. But he'd be certainly be vastly less effective at all that as vice president.

As vice president, he would be a soldier in the Romney White House -- which most everyone expects to be cautious, pragmatic and dominated by establishment figures. In the Romney White House, CEO Mitt Romney will set the strategy, and there's little evidence that his instincts match Ryan's preference for detailed, sweeping plans. So conservatives would have taken Ryan out of the House, where he's proven himself able to drive the Republican Party's agenda and force presidential candidates to sign onto his vision, and jammed him into a subordinate role in the executive branch, where he'd be duty-bound to fall in line behind President Romney's agenda.

Conversely, as House budget chairman -- or, potentially, ways and means chairman -- Ryan can be a conservative check on the Romney White House. They'll have to negotiate their policies with him, they'll be so afraid of disapproval that they'll always get his sign-off first, and, if they try and end-run him, he can always go to the media or simply corner them by using his influence among House Republicans to send the Romney White House legislation that goes further than it really wants to go.

Actually, all that's another reason Romney might want to pick Ryan. His life as president is likely to be a lot easier with Ryan inside his administration than outside of it. But it seems, again, like a bad outcome for the conservatives pushing this choice.

Ezra Klein writes for The Washington Post.