The Washington Post's Aaron Blake makes the case against Rick Santorum as a viable presidential candidate. It's a good read, but this assertion struck me as a little too strong.
Republicans have a long history of picking candidates they are very familiar with — often people who have run for president before and lost. People aren't familiar with Santorum, and he's got a reputation as a wild card. With so much on the line for a Republican Party hell-bent on beating President Obama in 2012, it would be entirely uncharacteristic of GOP voters to hand the keys to a candidate as untested on the national presidential stage as Santorum.
Since 1960, there have been seven presidential contests where the Republican field was completely open: 1960, 1964, 1968, 1980, 1988, 1996, 2000, 2008. If you exclude years that involve a sitting vice president, 1960 and 1988, that winnows the sample size down to six presidential contests. Between these five contests, have GOP primary voters been inordinately fond of nominating familiar faces? It's hard to say. So far, political insiders are four for six in Republican presidential primaries: Richard Nixon in 1968, Ronald Reagan in 1980, Bob Dole in 1996 and John McCain in 2008. By and large, both Barry Goldwater and George W. Bush were relative newcomers to national politics.
This is all to say that Rick Santorum isn't particularly disadvantaged an "inexperienced" candidate. Given the right circumstances, GOP primary voters are completely willing to choose a new face. Insofar that Santorum has a problem, it's with cautious Republican elites, who might not be enamored with his unmitigated extremism on social issues.