House Republicans pushed an election-year vote Wednesday to repeal President Barack Obama's health care overhaul, casting it as not only a rejection of an unpopular law but a surefire way to block a tax on the middle class.

"The intent of the president's health care law was to lower costs and help create jobs. One congressional leader promised it would create 400,000 jobs," said House Speaker John Boehner, R-Ohio. "Instead, it is making our economy worse, driving up costs and making it harder for small businesses to hire."

The House has voted more than 30 times to scrap, defund or undercut the law since Obama signed it in March 2010, political moves that went nowhere in the Democratic-controlled Senate. The House GOP leadership staged another symbolic repeal vote with a fresh argument courtesy of the Supreme Court.

Two weeks ago, Chief Justice John Roberts wrote in his majority opinion that the law was constitutional because it imposes a tax — not a penalty — on people who refuse to buy insurance. Republicans who repeatedly pressed for repeal said a "yes" vote would not only overturn the law but spare some 20 million Americans from an unnecessary tax.

Democrats mocked Republicans for insisting on repeal without offering a replacement.

Standing on the House floor, Rep. Al Green, D-Texas, held the 2,700-plus page bill in one hand and said he had the GOP alternative in his other hand. He waved an empty right hand.

"Empirical evidence against the invisible evidence," Green said.

The Affordable Care Act, Obama's signature domestic achievement, would extend coverage to about 30 million of the estimated 50 million uninsured. But two years after its enactment, polling shows that it remains unpopular and highly divisive among the American people. The law contributed to the defeat of many House Democrats in the 2010 elections and the party's loss of majority control.

Still, House Democratic leader Nancy Pelosi dismissed the election-year implications.

"The politics be damned. We came here to do a job," Pelosi told reporters at a Capitol Hill news conference in which various individuals, including some with illnesses, offered their gratitude for the law.

Under the act, Americans who don't get qualified health insurance will be required to pay the penalty — or tax — starting for the 2014 tax year, unless they are exempt because of low income, religious beliefs or because they are members of American Indian tribes. The penalty will be fully phased in by 2016, when it will be $695 for each uninsured adult or 2.5 percent of family income, whichever is greater, up to $12,500.

Democrats circulated a memorandum with a series of quotes from likely Republican presidential nominee Mitt Romney in which he defends the so-called individual mandate of the Massachusetts' health care law that he secured as governor. Obama's law was closely modeled on the universal-coverage plan that Romney instituted in his state. That plan penalized people who failed to comply with the requirement to buy insurance, just like the Obama overhaul will do.

Romney, the Democrats pointed out, said in June 2005 that "everyone must either become insured or maintain adequate savings to cover their medical expenses. We cannot expect some citizens to pay for others who can afford to pay some or all of their own way."

Appearing before the NAACP's annual meeting in Houston, Romney was booed when he pledged to repeal the health care law.

Democrats have argued that the two days of House debate and vote were a waste of time because the Democratic-led Senate wouldn't vote for repeal, the Supreme Court had rendered its judgment and voters want Congress to focus on more pressing issues such as the sluggish economy.

"As a psychiatrist, I'm qualified to say this," said Rep. Jim McDermott, D-Wash. "One definition of insanity is doing the same thing over and over again and expecting a different result. The game is over. The referee, John Roberts, blew the whistle. It's over, guys."

Although the outcome isn't in doubt, the vote provides plenty of election-year fodder, energizing the political base and helping to attract campaign dollars. House Whip Kevin McCarthy, R-Calif., said a number of Democrats would join Republicans in voting to repeal the law.

In fact, many of the Democrats who backed the overhaul lost their seats in the 2010 elections. Those who are left would be open to charges of flip-flopping if they switch their votes.

Democrats argued that erasing the law would eliminate the more popular individual elements — a guarantee on coverage for those with pre-existing medical conditions, a requirement allowing children up to age 26 to remain on their parents' coverage and the reduction of seniors' Medicare prescription drug costs by closing the "doughnut hole" coverage gap.

Republicans insisted they were keeping a promise with Americans to repeal the law.

"This is a law that the American people did not want when it was passed and it remains a law that the American people do not want now," said House Majority Leader Eric Cantor, R-Va.