Updated: June 15, 7:23 p.m.

House Republicans successfully exposed lingering divisions within the Democratic Caucus over a health insurance mandate by forcing a vote Tuesday on a proposal to repeal that part of the new health care law.

Twenty-one Democrats voted in favor of the repeal proposal, which Ways and Means ranking member Dave Camp (R-Mich.) offered as an amendment to legislation that would provide tax breaks to small businesses. But the proposal was roundly defeated, 187-230, and the House went on to pass the small-business bill, 247-170.

Despite the defections, Democratic aides insisted that the vote signified growing support for the health care bill, which was opposed by 34 Democrats in March.

One Republican, Anh “Joseph” Cao (La.), voted against Camp’s proposal to repeal the insurance mandate on individuals. Cao also was the lone GOP lawmaker to vote for the health care bill.

Camp opposed the small-business bill and said his proposal would provide “real help to Americans by repealing one of the most onerous provisions of the new health care law.”

“No American should be forced to buy or purchase health insurance that they don’t want,” he said.

Democratic opponents of Camp’s proposal argued that doing away with the individual mandate would deprive 16 million Americans of health insurance coverage.

The individual mandate was a central flash point in the protracted debate over remaking the nation’s health care system, which was President Barack Obama’s signature item on his first-term legislative agenda. Under the new law, every American must participate in a qualified health care plan or pay a penalty.

Ways and Means Chairman Sander Levin (D-Mich.) defended the individual mandate and blasted Camp’s proposal as “nothing more than a disingenuous political stunt to undermine health reform.”

Doug Thornell, a spokesman for Assistant to the Speaker Chris Van Hollen (D-Md.), called the GOP proposal hypocritical. “Washington Republicans tried to repeal one of the few decent health care ideas they have come up with — the individual mandate. This was at the heart of Romneycare in Massachusetts and the GOP health proposal in ’93,” he said.

GOP lawmakers have launched an election-year strategy based around advocating repeal of the law, and Camp’s proposal was posted Tuesday on americaspeakingout.com, a website House Republicans set up as a platform for the public to share policy ideas.

Republicans immediately seized on the widespread Democratic opposition to their proposal and tried to paint the majority as out of touch with public sentiment.

“The American people have rejected the president’s government takeover of health care but Washington Democrats are not listening,” Republican Conference Chairman Mike Pence (Ind.) said in a statement. “House Republicans have been listening to the American people. Through AmericaSpeakingOut.com, town halls, emails and phone calls, we know that taxpayers want Washington to repeal the government takeover of health care.”

Minority Leader John Boehner (R-Ohio) cast the GOP proposal as “the biggest vote on the new health care law since it passed.”

“This is a first step in Republicans’ efforts to repeal ObamaCare and replace it with commonsense, step-by-step reforms to lower costs,” Boehner said in a statement prior to the vote.