Republicans like Dark Horse presidential candidates, especially ones championing a cultural populist approach. In 2008, Mike Huckabee, then a little-known Arkansas governor, beat out better-funded, more prominent rivals to finish as the runner up for the nomination. In 2012, former Sen. Rick Santorum, out of public office for five years, came back from the political dead to be Mitt Romney’s main rival for the GOP nod.

Their success has many parallels and could serve as a model for future candidates.

Huckabee and Santorum were the most outspoken social conservatives in their contests. Both appealed to blue-collar workers who are not natural Republican primary voters. Santorum has been able to capture the support of Huckabee’s Southern Evangelical base—a feat for an Italian Catholic from suburban Pittsburgh. In Southern contests, Santorum was able to run just as strong in the Jacksonian uplands of Alabama and Tennessee, and he did better in the coastal and urban areas like Birmingham, Nashville and Mobile.

Santorum has been able to outperform Huckabee in some areas, including Northern rural counties. This was most apparent in Michigan. Huckabee got nowhere in Michigan in 2008. He got sixteen percent and did not win a single county. Even heavily evangelical Ottawa County only gave him 23 percent. Santorum had much broader appeal. He earned 38 percent in Michigan, won most of the rural counties, and got 49 percent in Ottawa County. Santorum has done better across the board in the North, even with evangelicals.

Huckabee demonstrated little appeal to Catholic voters. He won just nine percent of Catholics in Michigan. In Louisiana, the governor took just 29 percent compared to Sen. John McCain’s (R-Ariz.) 55 percent. By comparison, Santorum got 37 percent of Catholic votes in Michigan and 46 percent in Louisiana.

Still, the most prominent Catholic GOP politician of his generation is losing his coreligionists to Romney. In Michigan, Romney received 44 percent of the Catholic vote, seven points ahead of Santorum. In Ohio, where Santorum lost by one point, Romney won Catholics 44 to 31 percent. Santorum was able to break free of Huckabee’s evangelical-only appeal, but wasn’t able to score even ties with Romney among Catholics, which would have been enough to upend the nomination race.

Santorum’s strategy also failed because he didn’t make enough inroads with blue-collar workers. In industrial counties such as Scott (Davenport) and Dubuque counties in Iowa, Saginaw and Bay counties in Michigan, and Mahoning (Youngstown) and Trumbull counties in Ohio, the Massachusetts millionaire beat the grandson of a coal miner. It may be the case that this approach is better suited to winning over independents than Republican primary voters.

What we have seen in the past two Republican presidential primary contests is that positioning yourself as the cultural populist outsider has become the most effective way to rival the best-known, best-funded candidates. The approach does have its flaws, though. Huckabee was never able to appeal beyond his Southern evangelical base. Santorum was able to run strong among Northern rural voters but still came up short in big contests. In spite of their failures, the Huckabee and Santorum experiences suggest that a better caliber cultural populist with broader appeal could be a leading contender for the Republican nomination in the future.

Chris Palko works as an assistant media analyst at Smart Media Group, a Republican political media buying agency in Alexandria, Va. He is a graduate of American University and George Washington University’s Graduate School of Political Management.

A version of this post was also published on Smart Media Group’s blog, Smart Blog.