By Mark Felsenthal
BOSTON (Reuters) - President Barack Obama, fighting to protect his party's margin of control in the U.S. Senate, urged Massachusetts voters on Wednesday to back fellow Democrat Edward Markey in a June 25 special election that could gauge Americans' views of controversies vexing Obama's administration.
With a Republican victory in a 2010 Senate special election still fresh on the minds of Democrats in a state that usually favors them, Obama spoke at a rally in Boston and with patrons at a locally famous sandwich shop to try to boost Markey's bid.
Polls show the lead held by Markey, a veteran U.S. congressman, over Republican challenger Gabriel Gomez is narrowing ahead of the election for the Senate seat vacated when Obama picked John Kerry, a Democrat, as his secretary of state.
"This election's going to come down to turnout," Obama told hundreds of Democrats at a rally at Roxbury Community College.
"We've got a whole lot of Democrats in this state and a whole lot of Obama voters. But you can't just turn out during a presidential election," Obama said.
"You can't just pat your back and say, 'Well, I knocked on some doors back in November.' I need you knocking on some doors right now, in June," Obama added.
Before his speech, Obama ordered a burger and fries at Charlie's Sandwich Shoppe, a tiny South End eatery, and urged patrons to support Markey.
"This guy has been fighting for Massachusetts for a very long time," Obama said with his hand on Markey's shoulder as patrons crowded around him. "It seems like there's an election every other week, but this one's important."
A liberal Democrat, Markey has represented the Democratic-leaning state in the House of Representative since 1976 and has won re-election by large margins.
The result of the election could indicate the extent of the political damage to Obama and the Democrats from a string of recent controversies. They include: the IRS targeting of conservative groups for special scrutiny; the Justice Department seizure of Associated Press phone records; disclosures about the attack last year on a U.S. compound in Libya; and revelations of sweeping surveillance programs by the U.S. government.
Obama steered clear of those matters during his speech, instead touting his victories on healthcare and financial services reform, and explaining he needed more Democrats like Markey in Congress to support his efforts on issues like gun control.
"He's not somebody who comes out of nowhere," Obama said, taking a swipe at Gomez, a former private equity executive and former Navy SEAL who has sought to make Markey's long tenure in Congress a liability.
A Suffolk University poll on Monday showed Markey holding a 48 percent to 41 percent lead over Gomez, down from a 52 percent to 40 percent margin the previous week.
Obama remains popular nationally, but the controversies are weighing on his approval ratings, Suffolk University Political Research Center Director David Paleologos said.
Republicans are fighting hard to gain the seat in the 100-member Senate, currently controlled by a majority 52 Democrats and two independents who caucus with them. Republicans have sought to block many of Obama's major legislative initiatives.
First lady Michelle Obama campaigned for Markey in the state last month. The Boston Globe reported that former President Bill Clinton would visit this weekend.
Democrats want to avoid a repeat of the upset victory in Massachusetts by Republican Scott Brown over state Attorney General Martha Coakley in 2010 in the special election for the seat left open after the death of long-time U.S. Senator Edward Kennedy. Coakley was faulted for running a lackluster campaign and failing to counter the everyman appeal of Brown.
Vice President Joe Biden and former Vice President Al Gore spoke at a Markey fundraiser in the state on Tuesday.
"Barack Obama's not at the head of the ticket. And that means those legions of African-Americans and Latinos are not automatically going to come out," Biden said. "So don't take this one for granted."
(Reporting by Mark Felsenthal; Editing by Will Dunham)