Scott Walker may have said it best. Fresh off beating back a recall election that was a direct challenge to his agenda of balancing the budget by undercutting public unions, the governor of Wisconsin implored Mitt Romney to be bolder.

"I think the mistake that they've made is the feeling like it can just be a referendum on the president," Walker said of the Romney campaign during a late July media appearance.

Walker was not alone in voicing such a concern. Mitt Romney had always been the sort of safe, Las Vegas oddsmaker's candidate: Despite his blandness and ideological malleability, he seemed to have the best chance of prevailing come November. Primary voters reluctantly got on board, as did the Republican establishment.

But Romney's securing the nomination has done little to dispel concerns that he has run a campaign without substance, constructed on the flimsy foundation of a "talk about the economy, attack Obama" mantra. Speaker of the House John Boehner admitted that "the American people probably aren't going to fall in love with Mitt Romney," and the Wall Street Journal rebuked Romney for thinking he could "play it safe and coast to the White House."

Choosing Tim Pawlenty or Rob Portman to be vice president would have maintained the Romney headquarters' cautious blueprint, offering an uncontroversial running mate who could provide a swing state boost.

The Paul Ryan pick has utterly upended that status quo. Suddenly, the election is not just a referendum on the Obama economy. Romney has chosen a man anointed by party elders and Beltway intelligentsia alike as the standard-bearer for a sweeping new vision of government, one that has become de facto party doctrine for the Republicans.

There was a telling moment at the Ryan rollout when Romney accidentally introduced his new running mate as "the next president of the United States." Romney quickly corrected himself, but the implication is clear: Ryan's policy ideas, embodied in his budget proposal, have become the guiding party ideology, and they will dictate what type of legislation a Republican president will champion and sign.

That budget, of course, has been enormously controversial. It would cut deeply into programs like Medicaid, education spending and food stamps while leaving military spending intact; it proposes tax cuts that would favor the wealthy and seeks to convert Medicate into a voucher program.

No less a luminary of conservative though than Newt Gingrich blasted the document as an example of "right-wing social engineering." Republican Jane Corwin lost a special House election in a conservative upstate New York district in part because her opponent, Democrat Kathy Hochul, relentlessly pummeled Corwin for her connection to the Ryan plan, constantly pointing out that it would weaken Medicare.

President Barack Obama has described Ryan's budget plan as a "radical vision" and "thinly veiled social Darwinism." The contrast between Obama and Ryan's respective platforms could hardly be starker: Obama has emphasized the government's role in promoting economic prosperity and fairness with a progressive tax code and investments in research, education, infrastructure and energy innovation.

Ryan, on the other hand, has produced a budget that resonates to the heart of the Tea Party-inflected Congress he helped build. It rests on the twin premises of drastically scaling back government spending and slashing taxes.

Romney has paid homage to those ideas throughout his presidential campaign, vowing to repeal legislation, like the Dodd-Frank financial reform bill and the Affordable Care Act, which Republicans see as budget-busting expansions of federal power. He has consistently called for fewer regulations and lower taxes.

But he has generally been vague on the specifics, content to deflect questions about the details by citing Obama's uneven economic record. Romney did not have to be the second coming of Ronald Reagan; he just had to be a Not Obama who said the right things.

Not any more. Ryan's elevation raises the stakes, turning this election into what Obama has sought to cast it as for months: a choice between competing ideals of what American government should be.