Gyory: Where does Paul Ryan fit in with decades of social science research?

Mitt Romney's pick of Wisconsin Rep. Paul Ryan as his running mate is a bold boom-or-bust move.

The potential boom is easy to spot: Ryan is whip-smart on budget numbers, telegenic with a squeaky clean family, and he hails from the Midwest so crucial in the Electoral College. Perhaps most important, his selection finally solidifies Romney's standing with his party's dominant right-wing base. But to avoid the bust, Romney and Ryan will have to navigate past some tough challenges.

For one, Ryan has never run for an office larger than a congressional district. National candidates need seasoned reflexes, to instantly calibrate how their words and actions will appear to the entire country.

What's more, Romney's selection of Ryan reignites the tax issue. Ryan is the author of the House of Representatives' budget plan, which prioritizes tax cuts and shrinking government over deficit reduction. While Ryan has been quite specific on what he would cut, he is vague on the tax reform side. An analysis of his plan by the Urban Institute, a Washington think tank, projects that there are simply not enough loopholes to keep the Ryan plan viable. Romney's camp has said the former governor is "putting together his own plan," but any debate that follows about taxes could also add grease to the fire over whether Romney should release multiple years' tax returns.

Which brings us to the third challenge. For decades, data developed by social researchers Hadley Cantril and Lloyd Free have been accepted by pollsters and political scientists as the best measure of the American electorate's philosophy. The results of their surveys of public opinion have consistently revealed that Americans are "ideologically conservative," but "operationally liberal."

That means that if issues are defined philosophically, the conservatives have the edge, but programs and policies related to Social Security, Medicare and raising the minimum wage prove popular. Interestingly, the nation's balance has remained remarkably consistent: In 1965, the Cantril-Free data revealed only 17 percent of Americans were ideologically liberal -- but 65 percent supported those specific government programs that would put them in the "operationally liberal" camp. When that same measure was used again in 2010, 20 percent were found ideologically liberal -- just a slight increase -- but the same 65 percent were found to be operationally liberal.

Republicans have learned that if they keep issues to ideology, they win -- consider the defeat of president Bill Clinton's health plan in 1994, and the party's gains in the House and Senate during the fight over Obamacare in 2010 -- but if they get too specific on cutting popular programs, they lose -- such as Barry Goldwater's opposition to Social Security in 1964, and Bob Dole's efforts to cut Medicare and Medicaid in 1995, which he couldn't shake the next year even after changing his position.

We don't have to wonder how Ryan's Medicare plan -- which would replace the program for those now younger than 55 with vouchers that would not likely maintain the current level of coverage -- plays politically. In May 2011, in a Western New York congressional special election, Democrat Kathy Hochul pulled off an upset victory after she transformed her campaign into a litmus test on Ryan's Medicare plan. Hochul's win in a bedrock Republican district could foreshadow problems for the Romney-Ryan ticket from Maine to Minnesota, that crucial northern land mass Obama needs to connect the Democrats' bicoastal coalition. If Ryan's Medicare stance sinks Romney in Ohio and Florida, then his gamble on Ryan will have failed.

Ryan on the ticket could also provide Democrats in House races with a magnet for pulling back the older white voters who went for the GOP in 2010. How ironic if the addition of the House GOP's intellectual star, Paul Ryan, to the national ticket, put the GOP's current House majority truly in jeopardy for the first time.

Ryan is unlikely to be a neutral factor for the Romney campaign. There's a huge upside for Romney, given Ryan's policy prowess and his vibrant down-home appeal. But there is also a downside to Ryan's assault on the gravitational forces underlying the political equilibrium on tax equity and Medicare. It will be fascinating to see whether Romney's daring selection ultimately proves a boom or bust.