He put his foot in it—by now we’ve come to expect that. After appearing through a portal in the grand old U.S.S. Wisconsin at the National Maritime Museum in Norfolk, Virginia, and describing his choice of running mate as a good Catholic who “believes in the worth of human life”—nudge, nudge you wary Evangelicals—he went on to introduce Congressman Paul Ryan as “the next President of the United States” and left the podium.

For a moment, I entertained the thought that the Mittster was quitting the race and throwing his delegates behind the forty-two-year-old Wisconsin visionary. After the beating he’s taken over the past couple of months, who could blame him? But no, here he was again, putting his arm around Ryan. “Every now and then, I’ve been known to make a mistake,” he said with a rueful smile. “But I didn’t make a mistake with this guy.”

We shall see about that. But Ryan did pretty well on his introduction. Tieless, tall, and angular, he looked around the crowd. “Wow, hey,” he said. “And right in front of the U.S.S. Wisconsin, huh. Man!” Doubtless, this aw-shucks demeanor is the mask of a professional Midwesterner, but he carried it off effectively, coupling it with some ingratiating remarks about Romney and some telling shots at the President. “High unemployment, lower income, and crushing debt is not the new normal,” he said. “It is a result of misguided policies.” He ended his speech with a ringing recitation of Republican themes—freedom, personal responsibility, and limited government. “What kind of country do we want? What kind of people do we want to be?” he asked. And he went on: “We can turn this thing around. We can.”

This performance wasn’t out of character. Ryan does a good job of cloaking his radicalism in unthreatening everyday language. He doesn’t foam at the mouth or get too academic. He doesn’t blather on about Friedrich Hayek or Saul Alinsky. As he was standing up there saying, “we won’t replace the founding principles, we’ll reapply them,” he looked more like the youthful general manager of a baseball team—a Theo Epstein or a Brian Cashman—than a committed ideologue.

The crowd cheered. The two families gathered around the podium for the television cameras. Kid Rock’s “Born Free” rang out. For a moment, all was well in the Republican world. On Fox News, Karl Rove called in from Oregon to give the choice his seal of approval. Ryan is a skillful communicator, he said—the failures in this area at the top of the ticket remained unstated—and together he and Romney would take it to the Obama campaign on the economy and the debt.

As my colleague Ryan Lizza said earlier, it’s a bold and brave choice, and for that Romney deserves some credit. In forgoing the play-it-safe options—Rob Portman and Tim Pawlenty—and picking the architect of a Republican plan to privatize Medicare, he has made the campaign more interesting, and more substantive. The historical fact remains that Vice-Presidential candidates rarely make any difference to the result. But the road to November suddenly looks quite a bit different.

A couple of days ago, I remarked that if Romney selected Ryan or Marco Rubio it would show that he was in trouble, and needed to shake up the campaign. That still seems right. In placing a lightning rod like Ryan on the ticket, Romney appears to have decided that the best form of defense is attack. For months, he and his campaign have been trying to turn the election exclusively into a referendum on Obama’s record. That strategy has now been abandoned. Ryan’s mere presence ensures that the election will be framed in the way that Team Obama has wanted all along: as a choice between the President’s moderate progressivism and the anti-government radicalism of today’s G.O.P.

Maybe Romney can mount a more effective campaign on this terrain of clashing ideologies. At the very least, it will energize Republican activists, many of whom view Ryan as a budding philosopher king—a Newt Gingrich without the arrogance or the girlfriends. A couple of years ago, when the Republicans took over the House of Representatives, I asked Grover Norquist, the Republican Svengali figure, what part Ryan would play in the coming legislative battle about the budget. Ryan wouldn’t get involved in the day-to-day wrangling, Norquist said; he was above all that: his role was to point the way to the promised land.

Another upside of picking Ryan, from Romney’s perspective, is that it will shift some of the attention away from him. Whether you love Ryan or hate him, he’s an interesting figure with provocative ideas, and he gets a lot of media ink. It may seem strange for a Presidential campaign to wish to divert attention from the Presidential candidate. In this case, though, things have come to that. With the media focussing so much on Romney’s taxes, his record at Bain Capital, and his gaffes, his campaign was listing badly.

Ryan’s selection changes the subject. That, at least, is what Stuart Stevens, Romney’s campaign manager, and spokesman Eric “Etch-a-Sketch” Fehrnstrom will be hoping for. So far, their effort to wipe out Romney’s record during the primaries and reset the campaign narrative along lines more favorable to him hasn’t been nearly as successful as they were hoping. Maybe throwing Ryan into the fray will help do the trick and transform the election into a debate about big government versus small government. That has to be the thinking in Boston. If the price is that his conservative ideas will turn off some moderate voters, it’s a price worth paying. These are desperate times.

Will the new strategy work? Even before Ryan and Romney had left the stage, the cable networks were dredging up details of his plans to reshape the retirement system. CNN asked Newt Gingrich whether he still considered it “right-wing social engineering.” There’s a lot more of that to come. Democrats like David Axelrod and Chuck Schumer like nothing more than scaremongering on Social Security and Medicare. And in this case, their scaremongering isn’t even scaremongering. The original Ryan budget plan did envisage getting rid of Medicare as it currently exists.

Straight after the Veep announcement, Romney’s campaign rushed out a set of talking points devoted to Ryan’s proposals. They said, “Gov. Romney applauds Paul Ryan for going in the right direction with his budget, and as president he will be putting together his own plan for cutting the deficit and putting the budget on a path to balance.” Axelrod responded on Twitter: “Wow, Mittsters break land speak record trying to distance from radical Ryan budget. Problem: it looks just like Mitt’s.”

So, going with Ryan is a big gamble, but it may well be one, as Alex Koppelman writes, that Romney had to take. The other day, I said he’s only got about three weeks to turn things around. He needed to pick a credible running mate, sharpen his message, and establish a connection with the voters. The selection of Ryan helps fill in the first two boxes, no doubt about it. Ultimately, though, it will be up to Romney to persuade the American people that he’s got what it takes. Judging by how he looked this morning, though, the presence of Ryan will help lift his spirits for the task ahead.

For more on Romney, Ryan, and the rest of the campaign, bookmark The Political Scene, our hub for coverage of the 2012 election.

Photograph by Chip Somodevilla/Getty