WASHINGTON – Voters headed to the polls Tuesday in Michigan, the state where Mitt Romney grew up, his father served as governor and his lock on victory in the Republican primary once seemed well-assured.But in the weeks since his main competitor, Rick Santorum, took Colorado, Missouri and Minnesota while Romney took Maine by only a slim margin, Romney’s lead in the polls has evaporated and put him well below Santorum for several days, until the two reached a statistical dead heat entering Tuesday’s contest.Responding on Sunday to a television clip on an ABC talk show, Santorum slammed the landmark speech on the separation of church and state given by John F. Kennedy, a Catholic, during his own presidential run.“What kind of country do we live [in] that says only people of non-faith can come into the public square and make their case?” Santorum said.“That makes me throw up and it should make every American [do the same].”“I don’t believe in an America where the separation of church and state is absolute,” he said. “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.”The following day, the Anti-Defamation League condemned Santorum’s comments.“Senator Santorum’s remarks on the need for more religion in politics are deeply disturbing and show a profound misunderstanding of the First Amendment,” the ADL’s statement said. “In a religiously diverse and pluralistic democracy, people of one faith should not seek to use the power of the government to impose their views on people of other faiths or of no faith. This message is as important today as it was when candidate Kennedy faced anti-Catholic bigotry as he sought the presidency in 1960.”On Tuesday, Santorum reportedly expressed regret for saying he wanted to “throw up” because of the speech.John Russo, co-director of the Center for Working Class Studies at Ohio’s Youngstown State University, said that while Santorum’s recent statements were likely to repel some types of voters, social issues could play an outsize role with conservative, working class constituents who feel that both parties’ economic policies have failed them – and like what Santorum has to say.“The working class moves more to social and wedge issues when they feel there’s not a great deal of difference between the two parties,” he said at a briefing for the foreign media. “The sense of it is that Santorum’s ideas have much more appeal among working class voters, especially working class voters that have different religious identities.”“If you’re a Catholic, white, working class voter and you’re very devout, there may be a real appeal to the ideas that Santorum is putting together,” Russo added. But he predicted that Santorum’s statements could have repercussions in the general election, should he win the nomination.“The real danger for this, for the Republicans, is that if they cater to the most conservative elements of the party, it’s going to make it very difficult for them to win in November,” he said, referring specifically to his home state of Ohio, a key swing state due to its diverse constituency. Ohio is often seen as a bellwether for who will win the national contest.Democrats have viewed Santorum’s rise and his positions on social issues – many of which are perceived as far outside the mainstream – as something that could be used to US President Barack Obama’s benefit. Some reports have detailed efforts to convince Democrats to vote for Santorum at the primary, which is open to voters from any party, in the hopes that Obama would eventually face a candidate they perceive as weaker.Russo said that he could not assess how effective the effort has been, but said it could make a difference in the outcome. He added that a loss in Michigan for any reason would be a tremendous setback for Romney.“I think it is going to be very difficult for Romney to move forward if that happens,” Russo said, adding that the fact that the race has been so tight – in a state so connected to Romney – casts doubts on his campaign even if he pulls out a victory.“I think that the closeness of the election in Michigan even says something about the difficulties that Romney is in,” Russo said.Romney was still heavily favored to win in Arizona – the other state voting Tuesday – according to polls there, but Michigan is seen as the larger prize.A victory for Santorum there could upend the entire Republican race, since knocking off Romney in his home state would send a devastating blow to his campaign.Santorum has been attempting to exploit Romney’s weakness with working class voters, who have been particularly hard hit by the economic crisis in the manufacturing-heavy northern Midwest state.Santorum has also tried to drive home differences on religious and social issues, which have made evangelical voters – of whom there are many in Michigan – wary of Romney, who expressed more liberal views when he served as governor of Massachusetts, although he has since walked back from many of them.