Mitt Romney has bowed to the backseat drivers in the conservative establishment, who for weeks have been slamming his listless and play-it-safe campaign.
The Republican nominee's choice of Wisconsin congressman Paul Ryan as his vice-presidential running mate is an acknowledgement that his low-key approach to winning the White House has left him treading water. But it comes with big risks.
The boyish Mr. Ryan, the leader of a new generation of Republican budget hawks, is a polarizing figure in U.S. politics. Though he is still not well known by most Americans, he might just emerge as an intellectual version of Sarah Palin, the 2008 running mate who provoked her critics as much as she indulged her fans.
Mr. Ryan, simply put, is the Tea Party's favourite nerd.
As such, his choice for the ticket suggests a strategic shift by Mr. Romney, who had sought to make this election almost entirely about President Barack Obama's economic record, offering few specifics about how he would govern differently. But that approach has so far left the GOP base frustrated and swing voters unimpressed.
By putting Mr. Ryan on the ticket, Mr. Romney is throwing in his lot with the right-wing of his party, a move that could alienate independent voters in the middle of the spectrum.
Mr. Ryan is the architect of the most fundamental and ideologically-tinged blueprint for reforming the U.S. welfare state in decades. His so-called Ryan budget, adopted by the Republican-led House of Representatives, would transform Medicare into a defined-benefit program, forcing future seniors to pay more out of pocket for their health care.
That has earned Mr. Ryan, an earnest 42-year-old first elected to Congress at only 28, hero status among the conservative intelligentsia. Just this week, the Wall Street Journal and National Review again called on Mr. Romney to name Mr. Ryan to the ticket.
In doing so, Mr. Romney has made his conservative critics ecstatic. Though the Romney campaign stressed that the GOP nominee would soon put forward his own budget plan, he is now joined at the hip with Mr. Ryan. For the right, Mr. Romney now emerges as an aggressive reformer with a radical plan to shrink the federal government.
"The Romney who picked Paul Ryan as his vice presidential running mate is an entirely different person," The Weekly Standard's Fred Barnes wrote after Mr. Romney's Saturday morning announcement. "He's prepared to take the fight to Obama on the biggest bundle of issues – spending, debt, the deficit, taxes, entitlements, and the reversing of America's accelerating decline under Obama."
The question is whether voter concern over the $16-trillion (U.S.) federal debt is enough for them to embrace the tough medicine proposed by Mr. Ryan. The Obama campaign is already accusing Republicans of wanting to "end Medicare as we know it." The choice of Mr. Ryan feeds into the depictions of the Republicans as cold-hearted number crunchers.
While the choice of Mr. Ryan has brought conservative opinion makers onside with the Romney campaign, however, there is bound to be considerable fall out in other spheres of the party.
Those hoping Mr. Romney would choose Florida Senator Marco Rubio as his running mate, among them former Florida governor Jeb Bush, are bound to be disappointed.
Wisconsin has become ground zero in the battle to rein in the benefits of public sector unions and a state Mr. Romney would like to win in November. But Florida is more critical to winning the White House, with more than three times the electoral votes and a huge Hispanic population among whom the GOP desperately needs to make inroads.
Mr. Rubio, 41, has less Washington experience than Mr. Ryan, having been elected to Congress for the first time in 2010.
But the same cannot be said of Ohio Senator Rob Portman, who previously served in the House and held top cabinet positions in the George W. Bush White House.
Mr. Portman, 56, had been considered the leading contender to be Mr. Romney's running mate. He represents another state Mr. Romney must win in November. He also earned praise for his competence and affability. His blandness would have been an asset if Mr. Romney had sought to make the campaign about Mr. Obama, rather than the GOP ticket.
Mr. Romney, 65, will now be subject to some of the same second-guessing that dogged John McCain in 2008. While the choice of Ms. Palin led to a temporary bump in the polls for Mr. McCain, it soon raised questions about his judgment.
The vice-president is second in line to the presidency. Voters will now have to evaluate Mr. Ryan in that light, in addition to weighing his stand on public finances.
In picking a budget hawk such as Mr. Ryan, Mr. Romney appears to mimicking 1996 GOP nominee Bob Dole, who also struggled to win over the conservative establishment. Mr. Dole made up for it by choosing former congressman Jack Kemp as his running mate. Mr. Kemp was one of the party's most ardent champions of supply-side economics.
But Mr. Dole still lost the 1996 election, as the right split its support between him and Reform candidate Ross Perot.
Mr. Romney is obviously hoping Mr. Ryan will bring him a better result.