WASHINGTON — As protests aimed at shaming Wall Street continued near New York’s financial heart, they raised a tantalizing prospect for beleaguered liberals: Their side may, unexpectedly, be witnessing the redefinition of a coming election year that was supposed to be all about an “enthusiasm gap” for Democrats against charged-up Republicans.

President Barack Obama, asked at a White House news conference Thursday whether the Occupy Wall Street movement had potential as a tea party for the left, ducked that question. But his vice president, characteristically, didn’t mince words, and drew a direct connection between the two ideologically disparate protests.

The new movement, which has spread from Manhattan to other cities, has “a lot in common with the tea party,” Vice President Joe Biden said, speaking across town at a forum sponsored by the Atlantic magazine. Both, he said, grew out of a profound sense that the political system was badly out of whack. “We were bailing out the big guys” in the financial community, he said, while failing to fix the problems of hard-pressed, ordinary Americans.

With that possibility comes danger. Tea party voters have proved to be a decidedly mixed blessing for Republicans. They helped defeat Democratic candidates in 2010 but now are pulling GOP presidential candidates to the right in a way that may prove problematic in next year’s general election. Some Democratic strategists see a similar threat to their efforts to woo middle-of-the-road voters if the Democrats get too close to a street movement with radical elements that remains highly unpredictable.

Some of the risks were evident Wednesday night, when anti-Wall Street demonstrators clashed with baton-wielding police in New York, resulting in 23 arrests and video footage of authorities using force to subdue protesters.

“You don’t have to be a genius to see that you can overlay what is going on with Occupy Wall Street to energize and mobilize a Democratic base. So from that standpoint, it has enormous potential,” said Steve Rosenthal, a longtime liberal strategist. “How big it gets and where it goes, I think, is anybody’s guess.”

At the moment, there isn’t even a name for a broader movement that might evolve out of the protests. “The 99 percent” is one catchphrase used by demonstrators to contrast themselves with the 1 percent of Americans at the top of the income scale.

Liberals say the origin of the anti-Wall Street drive is more spontaneous and authentic than that of the tea party movement, which was boosted into existence by Fox News, a favored news source for conservatives. Another difference: Tea party followers were sharply focused on one issue — cutting government spending — while Occupy Wall Street is amorphous in its aims.

Beyond that, there are broad and potentially growing similarities. Both movements are decentralized and nonhierarchical, driven largely by an alienated and outraged citizenry that favors the same two-word phrase: fed up.

Robert Weissman, president of Public Citizen, an anti-corporate advocacy group, said it was “quite possible” that Occupy Wall Street could evolve into a political movement along the lines of the tea party.

He pointed to the recent decision by unions to join the protests, a development that could support the diffuse movement in the same way that several well-funded conservative organizations have aided tea party groups — but that also runs the risk of limiting Occupy Wall Street’s growth if it becomes too closely associated with labor.

Union officials, besieged after years of political decline and sensing an opportunity to rebound, have been careful to play down their involvement, which includes a mixture of manpower and logistical support.

“We have no intention of co-opting or taking over,” said Thea Lea, deputy chief of staff of the AFL-CIO in Washington. “That would be inappropriate and counter-productive.”

The unlikely success of the largely youthful protesters in attracting media attention has prompted a certain amount of envy among existing groups on the left, whose efforts to convert public anger against Wall Street into a voting force ahead of the 2012 election have gone largely unnoticed.

Members of the American Dream Movement, a liberal coalition led by MoveOn.org that has cast itself as a counter to the tea party, have threatened to field insurgent challengers to more conservative Democrats in next year’s election. Robert Borosage, an activist who is part of the group, praised Occupy Wall Street for “creating a moral space for others to carry (their protest) into the political realm.”

Stuart Appelbaum, a New York labor leader whose union gave blankets to protesters in a lower Manhattan park, said his conversations with the young people camped there convinced him that Occupy Wall Street wasn’t interested in “morphing into the sort of movement that the tea party has become.”

Some of the more radical anti-Wall Street activists are harshly critical of Obama and the Democrats for not doing more to rein in what they regard as unchecked greed in the financial sector, three years after the credit crisis began. And Justin Ruben, executive director of MoveOn.org, which helped recruit demonstrators from among its members, said many of those in the anti-Wall Street group wouldn’t be voting at all.

Ruben said his group wasn’t participating, as a way to help Obama. “But I think there’s an energized populist economic movement that’s growing, and that’s something that can help Obama if he continues to take up the fight. You’ve seen a huge shift since the beginning of August in the posture of the White House,” he said.