WASHINGTON -- Lawyers for the U.S. Justice Department and civil rights groups told a packed federal courtroom Monday that Republican legislators in South Carolina pushed a voter ID bill they knew would suppress the votes of African-Americans in the state, who overwhelmingly support Democratic candidates.

In often tense exchanges with the lawyers, the measure’s chief authors, state Rep. Alan Clemmons and state Sen. Chip Campsen, both Republicans, disputed accusations that racially linked partisanship was behind the law and said the legislation was meant to combat election fraud.

“In the voters’ mind, they look at the whole basket of fraud,” Clemmons testified. “They see it as undermining their vote regardless of the variety of fraud.”

South Carolina Gov. Nikki Haley signed the bill into law May 18, 2011. But the Justice Department blocked it as a violation of the Voting Rights Act, the landmark 1965 law that requires South Carolina and other states with Jim Crow pasts to submit all election changes to federal review.

South Carolina is suing Attorney General Eric Holder over his agency’s rejection of the voter ID law, which requires that residents of the state provide one of five types of photo identification in order to cast a ballot. They now can show a voter registration card with no photo.

Whichever way the three-judge panel hearing the case rules, it likely will be decided by the U.S. Supreme Court. The high court also might decide the fate of a similar law in Texas after a federal trial last month in which a separate panel of the U.S. District Court for the District of Columbia has yet to rule.

Lawyers opposing the South Carolina law displayed data from the State Election Commission that showed 178,000 registered voters don’t have a driver’s license, military tag or other form of photo ID required by the suspended law. The attorneys said that 36 percent of those without the approved identification are minority voters – the vast majority black and a larger share than their 30 percent share of the state’s overall population.

“Voting in South Carolina is racially polarized,” said Garrard Beeney, a New York lawyer representing civil rights groups that have intervened in the case to oppose the state law.

“If one impedes an African-American from voting, the overwhelming evidence is you are eliminating a vote for a Democrat,” Beeney said. “Race and politics in South Carolina are inextricably intertwined. It is purposeful discrimination, and it is unlawful under the Voting Rights Act.”

Christopher Bartolomucci, a former White House lawyer for President George W. Bush who is now with the Bancroft firm in Washington, argued that South Carolina has a moral right to ensure the legitimacy of its elections.

“The facts in this case will show that South Carolina’s voter ID law was enacted for important and legal purposes – to help prevent election fraud and to help increase public confidence in the electoral process,” Bartolomucci said.

Campsen, the South Carolina state senator who co-authored the law, testified for more than 4 1/2 hours, enduring 90 minutes of tough grilling from Beeney, a New York lawyer representing national interest groups that have intervened in the case against South Carolina. Among the groups are the NAACP and the American Civil Liberties Union.