As Mitt Romney piles up key endorsements, polls suggest that the Republican frontrunner is poised to win the upcoming Wisconsin primary on April 3rd.

A new NBC/Marist poll has Romney leading Rick Santorum by seven points in Wisconsin, closely paralleling a Marquette University Law School poll conducted earlier this week that gave Romney an eight-point advantage. 42 delegates are at stake.

The favorable polling data is the latest piece of evidence bolstering the perception that Romney will emerge as the Republican presidential nominee. The former Massachusetts governor has a substantial lead in pledged delegates, and he has secured some key nods from party figures this week.

Rep. Paul Ryan (R-WI), the House Budget Committee chair whose recently released budget proposal distils the party's guiding principles, announced his support on Friday morning. Ryan called for Republicans to close ranks behind Romney, suggesting that the bruising primary process, with Republican candidates  attacking one another with unprecedented animosity, is damaging the party's chances in the fall.

It is getting to the point where it's going to become counter-productive if the primary drags on, Ryan told the Milwaukee-Journal Sentinel. It's going to get much tougher to defeat Barack Obama in the fall.

Florida Senator Marco Rubio, an ascendant young lawmaker whose name often surfaces as a potential vice presidential pick, announced that he was backing Romney earlier this week. Another prominent Florida Republican, former governor Jeb Bush, had also called for the party to unify behind Romney.

A loss in Wisconsin could deal a serious blow to Santorum's campaign. The former Pennsylvania senator is campaigning across the state, working to strike a contrast with Romney by portraying himself as more in touch with working-class voters.

We need someone who can talk and relate to folks who are out there battling in this economy feeling like they're swimming alone, Santorum said, according to ABC News. Someone who can relate to them, who maybe doesn't talk about being the CEO of a company and having, you know, jokes about firing people.