Republican presidential hopeful Mitt Romney affirmed his frontrunner status on Tuesday when he won primary contests in the states of Arizona and Michigan. The former Massachusetts governor won all of Arizona’s 29 delegates for the nominating convention in August. Although he beat rival Rick Santorum narrowly in his home state of Michigan, both candidates picked up eleven delegates there.

Romney, who was born and raised in Michigan, won the state with a 9 percentage point lead over John McCain in the 2008 primary. That was before he said to oppose government support of two of the state’s largest car makers however. His margin of victory was just over 30,000 votes this time.

In a victory speech in Novi, Michigan, Romney said, “We didn’t win by a lot but we won by enough and that’s what counts.” He may as well have been summarizing his entire campaign.

Even if Santorum also opposed the auto bailouts, he was able to convey the image of a working man’s Republican who promised to reinvigorate manufacturing in America.

The grandson of a coal miner, Santorum, who was a senator for Pennsylvania, a traditional swing state with twenty electoral votes up for grabs in the fall, touts a tax reform plan that would disproportionately favor manufacturing companies. He rejects global warming as a leftist conspiracy and would allow energy companies to “drill everywhere” for oil and natural gas.

An afterthought in the primary race for all of 2011, Santorum staged a surprise victory in the Iowa caucuses in early January. Earlier this month, he won preelection contests in the Midwestern states of Minnesota and Missouri. According to opinion polls, he does well across the “Rust Belt” of America, once industrial states that have seen wages decline and jobs moved overseas.

Here, he says he could appeal to “Reagan Democrats” or union workers who may be tempted to vote Republican, as they voted for Ronald Reagan in the 1980s, if they perceive the Democratic candidate to be an elitist who is out-of-touch with their everyday struggles when the Republican speaks their language.

It is this very voting block that Romney has failed to enthuse. Political groups that are affiliated with the Democratic Party have gladly made use of his call to “let Detroit go bankrupt” in 2008 to portray the former businessman as a callous billionaire who doesn’t know about the plights of ordinary Americans.

Romney is perceived as a moderate, moreover, because he once favored abortion rights and implemented a health insurance scheme in Massachusetts when he was governor there that resembles President Obama’s unpopular health reform legislation. His nationwide support has hardly ever exceeded 25 percent. Just a third of right-wing voters believe that he’s the best candidate.

Among independents, too, Romney’s popularity is declining instead of improving which is a challenge to his campaign which likes to portray their candidate as the most electable among the four Republicans who are in the race.

Certainly, Rick Santorum would be harder pressed in a general election to sway centrist voters. His industrial policy may appeal to blue-collar voters who otherwise trend Democratic but his strong social conservatism worries even members of his own party.

On abortion, contraception and gay rights, including marriage, his beliefs do not align with the views of the majority of Americans.

Even if he promises not to craft policy based on his faith, Santorum rejects the total separation of church and state. “The idea that the church can have no influence or no involvement in the operation of the state is absolutely antithetical to the objectives and vision of our country,” he told ABC News’ This Week on Sunday.

Santorum championed welfare and Social Security reform as a senator but is far from the ideal, small-government conservative that the Republican base hungers for. He admitted as much in 2006 when he argued that most conservatives do not embrace the notion of personal autonomy. “Some do,” he admitted.

They have this idea that people should be left alone, be able to do whatever they want to do, government should keep our taxes down and keep our regulations low, that we shouldn’t get involved in the bedroom, we shouldn’t get involved in cultural issues. You know, people should do whatever they want.

According to Santorum, it is “not how traditional conservatives view the world” although this more libertarian view on what should be the role of government, especially in people’s personal lives, resonates across the political spectrum, from leftists to Ron Paul supporters.

By throwing a scare into Romney in a state where his father was once governor, Santorum did establish himself as the conservative alternative in the primary contest. Former House speaker Newt Gingrich must avenge himself in the South next week when ten states vote at once on Super Tuesday or become totally irrelevant.

Ohio, with 66 delegates, will be the main battleground state on February 6. If Romney wins here, he would prove his ability to appeal to both working-class voters and a critical swing state constituency. Ohio will have eighteen electoral votes in November.