BOSTON (AP) -- Former Gov. Mitt Romney looked to the loyalty of Massachusetts Republicans to carry him in his home state over surging Republican rival John McCain, while voters here had a tight race to settle between Democrats Barack Obama and Hillary Rodham Clinton.
Cold rain and sleet covered much of the state early Tuesday but officials still expected a record number of people to vote in the primary in Massachusetts, one of more than 20 electing delegates on Super Tuesday.
Whitman Police Sgt. Harry Bates said there were about 40 people waiting in line there when the polls opened at 7 a.m.
"For a primary, this is unusual," Bates said. "I think the competition on both sides -- that's enhanced the public interest in coming out for the primary."
A steady stream of voters entered a heavily democratic precinct in Boston's Jamaica Plain neighborhood. Outside, supporters of Senators Clinton and Obama held signs and shouted last-minute arguments.
Bob Poland, a 49-year-old travel agent, said he chose Clinton based on her experience.
"Obama seems like a nice guy, but I'm just worried he doesn't have enough experience to be president," said Poland, who also cited Clinton's stance on health care and economic issues.
In Topsfield, Marcia Spector described her decision to vote for Obama over Clinton as a difficult one.
"I just feel that he is dynamic and he is for change. He doesn't bring the baggage. I think he's more electable actually," said Spector, 58, an English as second language teacher.
Massachusetts Secretary of State William Galvin predicted a heavy turnout in both Democratic and Republican primaries, with more than 30 percent of the electorate showing up at the polls -- a number he said could climb even higher.
Massachusetts may seem like the ultimate Democratic stronghold, but the single largest group of voters here -- slightly more than half of the electorate -- are not enrolled in any party.
Independent voters in the state, who can vote in either the Democratic or Republican primary, make up 50.3 percent of the state's 4 million voters. Registered Democrats account for 36.8 percent and Republicans make up 12.1 percent. Smaller parties make up less than 1 percent.
Galvin said most independent voters would probably cast ballots in the Democratic race.
"I think they are more likely to break to the Democratic side, because most independent voters in Massachusetts have historically Democratic roots," he said. "But I think there will be a healthy independent voters on the Republican side."
Republican Mary Jordan said she didn't ultimately decide to vote for Romney until she entered the voting booth.
"I think he's the least unlikeable. I really didn't like any of them," said Jordan, a 43-year-old teacher's aide from Topsfield.
Monica Crowley, 40, said she couldn't vote Democrat because she doesn't like talk show host Oprah Winfrey, who supports Obama, and she opposed Clinton's health care plan.
Ultimately, she reasoned that McCain, a staunch supporter of the Iraq war, would actually be most likely to end the conflict because his son, Jimmy, is serving in Iraq.
"I can't believe after what he's been through and having (a son) there that he will allow it to continue," she said.
In Randolph, an elderly man drove over a sidewalk and struck an 8-year-old girl outside an elementary school being used as a polling place. Authorities say the man lost control of his SUV and drove through a crowd of kids, ultimately pinning the girl against the brick building. The girl was taken to a Boston hospital and her condition was not immediately known. Officials said voting was not disrupted for the two precincts that use the building.
Polls across the state are open until 8 p.m.