Mitt Romney and his just-named running mate, Rep. Paul Ryan, hit the campaign trail over the weekend, drawing huge and newly electrified crowds. Romney praised Ryan, the House Budget Committee chairman who's championed deep spending cuts, as a conservative visionary and poster child of fiscal responsibility. Democrats pounced on the selection, calling Ryan a genial but "extreme right-wing ideologue" whose controversial budget proposal, designed to overhaul Medicare and reduce tax rates for investors, would devastate working Americans while padding the pockets of the rich. How will adding Ryan to the mix change the presidential race? Here, six takes:

1. Romney now has the GOP base firmly behind him
Ryan instantly "generated enthusiasm among his party's fiscal conservatives," say Patrick O'Connor and Sarah Murray in The Wall Street Journal. The GOP base adores Ryan's plan to "rein in spending through budget cuts and changes to Medicare and other entitlement programs." Within 24 hours of his joining the ticket, the Romney campaign raked in $3.5 million in online donations. Tea Partiers had doubted Romney, says Michael D. Shear at The New York Times, but now that they can count his running mate as one of their own, the small government movement will focus unswervingly on electing the Romney-Ryan ticket.

2. But he can kiss Florida good-bye
Republicans aren't the only ones rejoicing over Romney's pick, says Marc Caputo in The Miami Herald. Democrats are hooting, too. Ryan's controversial budget plan "makes big changes to Medicare and Medicaid and could allow for some privatization of Social Security," and that's political poison in Florida, "a must-win state for Republicans." Polls show that voters over 50 — more than half the electorate in the Sunshine State — don't want anyone tinkering with these "liberal-legacy" programs.

3. At least now we'll get a serious debate
"Screw the polls," says William Saletan at Slate. Ryan recognizes that "our domestic spending trajectory is unsustainable" and that we'll fly off the cliff, just like Europe, if we don't get our debt under control with "serious budget cuts." Romney has just put himself "on the right side of the spending debate. Now, "instead of bickering" about his tax returns, we'll get a real debate about "serious problems and solutions. That’s great for the country."

4. Romney isn't playing it safe any more
Romney became a new candidate overnight, says A.B. Stoddard at The Hill. Before, he was "running a non-campaign on the hope that voters were simply ready, in such a troubled economy, to fire Obama." Suddenly, he's a "serious candidate" who is willing to do "something politically dangerous because he believes it is the right thing to do." By embracing Ryan's controversial policy heft, Romney has shown that he's going to "campaign on the urgent need for austerity and fiscal rescue," instead of trying to win by default.

5. This ups the stakes for both sides
Pairing Romney with the controversial Ryan "opens up an Obama landslide scenario for the first time," says Sean Trende at RealClearPolitics. Before, it looked like Obama could barely eke out a win. But Romney needs "an outsized share of downscale white voters" to win, and Ryan's plan could so completely alienate them that Obama might do even better than he did in 2008. The flip side, of course, is that vice presidential picks seldom tip elections, and this vote could still come down to a referendum on Obama and the economy. But if Romney wins with Ryan by his side, he'll be able to argue that he has a mandate to push through game-changing economic fixes like the ones in Ryan's budget.

6. Romney's VP pick dims his presidential hopes, but brightens Ryan's
Paul Ryan has a "Tobey Maguire–esque likeability" that Romney lacks, says Aaron Gell at the New York Observer. He's good-looking. He has serious domestic policy chops. And he just might cost Romney the race, because his (and now Romney's) "radical right-wing economic vision... will be an extremely hard sell to general election voters." But even if they lose, the campaign will establish Ryan as the "GOP's new intellectual heavyweight," so he'll be able to "comfort himself with the notion that he'll almost certainly emerge as the nationally tested frontrunner for the 2016 race."

Read more political coverage at The Week's 2012 Election Center.