Two states in the American West voted in the Republican Party’s presidential primary contest on Tuesday. Although many will be watching to see how well Newt Gingrich, the former House speaker who hopes to position himself as the right-wing alternative to the presumptive nominee, Mitt Romney, does, the third-tier candidates in the race probably have a better chance of asserting their viability.

Ron Paul and Rick Santorum vie for very different constituencies but could boost their electoral prospects in the states of Colorado and Minnesota, respectively.

After placing a disappointing third in Nevada’s caucuses over the weekend, Paul hopes that his message of limited government and a noninterventionist foreign policy will resonate with Colorado voters who tend to be more libertarian than Republican primary voters elsewhere.

The Colorado vote is closed to registered Republicans which is a disadvantage to the Texas congressman who appeals more to dissatisfied independents.

Minnesota’s caucuses are open to non-Republicans but evangelics and social conservatives are in the majority there. Newt Gingrich carried their vote in South Carolina and northwestern Florida in January and had an almost 20 percentage point lead over Mitt Romney in the Midwestern state that same month.

However, Gingrich is flagging which could be an opportunity for Rick Santorum to stage another victory. After winning in Iowa in early January, the former Pennsylvania senator has struggled to convince voters that he is the true conservative alternative to Mitt Romney. The frontrunner’s barrage of negative advertising against the former House speaker has significantly tarnished his right-wing credentials — perhaps enough to give Santorum an opening.

Between them, Colorado and Minnesota wield 76 delegates and they are awarded proportionately. Even if Romney wins in both, the other contenders should be able to accumulate delegates for the national convention in Tampa, Florida in August.

Gingrich and Paul have both vowed to stay in the race to the very end which raises the prospect of a brokered convention. If none of the presidential hopefuls manages to secure a majority of delegates before the convention, they could be unbound after several unsuccessful ballots and vote for someone who didn’t even participate in the primary contests.

There is also an election in Missouri but the outcome is officially meaningless. The state’s 52 delegates won’t be selected until March 17 when the state caucuses. Except for Santorum, the candidates haven’t given Missouri much attention for this reason. Gingrich isn’t even on the ballot. Still, if the state’s religious voters give him another win, even if it’s effectively an opinion poll, it could reinvigorate Santorum’s campaign which has thus far been little more than an afterthought in the primary race.