WASHINGTON — A federal trial opening today will examine the legality of South Carolina’s new voter ID law and also put on display the state’s history of racial discrimination.

The question: Has that history of racially charged politics faded into irrelevance? Or is the state still stacking the deck against black residents?

Dozens of S.C. legislators, officials, professors and interest group leaders will testify for five days under questioning by attorneys from a Washington law firm representing South Carolina and by civil rights lawyers with the Justice Department.

Among the legislators testifying will be the voter ID bill’s chief sponsors, Republican state Reps. Alan Clemmons of Myrtle Beach and Chip Campsen of Charleston, and a leading opponent, Democratic state Sen. John Scott of Columbia.

Scott, who is black, will testify that he was excluded from final deliberations on the voter ID law as part of what he says was a broad plan by GOP legislators to suppress Democratic voters.

“Based on approximately 25 years of experience in the (S.C.) Senate and House of Representatives combined, I believe that the members of the General Assembly knew that minorities are overwhelmingly likely to vote Democratic,” Scott said in advance written testimony. “I also believe that the members of the General Assembly expected the voter ID bill to lead to lower turnout among minority voters.”

Clemmons and Campsen didn’t submit advance testimony. Campsen declined to discuss the case.

After hearing the testimony, a panel of three judges — two appointed by former President George W. Bush, one by former President Bill Clinton — is expected to rule in early fall.

They must decide whether the law, enacted last year but blocked by the Justice Department, violates the 1965 Voting Rights Act.

The federal government’s top civil rights lawyer, U.S. Assistant Attorney General Thomas E. Perez, will argue that the law violates the Voting Rights Act, which Congress extended in 2006 for 25 years, because it would disenfranchise large numbers of black and minority voters.

“The United States will show that the impact of requiring photo identification to vote a regular, in-person ballot will fall far more heavily on African-Americans, and that South Carolina legislators knew, given the data provided by the State Election Commission, that this would be the case,” Perez wrote in a pretrial brief filed Tuesday.

Paul D. Clement, a former U.S. solicitor general under President George W. Bush, will respond on behalf of South Carolina that the voter ID law isn’t discriminatory and has a legitimate, colorblind aim of preventing voter fraud.

“Act R54 is not the cause of any disparity in the rates of possession of photo ID by registered voters,” Clement said in his pretrial brief. “The Act will neither disproportionately affect nor impose a material burden on minority voters.”

Addressing the racial currents at the core of the case, Clement will argue that South Carolina’s Jim Crow era should not be held against the state in judging the fairness and legality of the voter ID law.

“Looking more broadly at South Carolina’s recent history, it is clear that the state has come a long way from the 1960s,” Clement wrote in his brief.

As proof, Clement noted that S.C. Gov. Nikki Haley, who signed the voter ID law in May, is “the first minority governor in the state’s history.” Haley is the daughter of Indian immigrants.

Clement will be joined in defending South Carolina by Christopher Bartolomucci, a White House lawyer under Bush. Both men work for the Bancroft firm, a prominent Washington legal group that focuses on cases likely to go to federal appellate courts or the U.S. Supreme Court.

Regardless of how the three-judge panel rules, the S.C. law is expected to end up before the U.S. Supreme Court. The high court also is likely to decide the fate of a Texas state voter ID law.

To rebut the claim of racial progress in South Carolina, lawyers for civil rights groups, which oppose the voter ID law, filed a list of 21 cases, going back to 1980, in which federal courts found evidence of racial discrimination in the state. Among the groups are the NAACP, the American Civil Liberties Union and the Lawyers’ Committee for Civil Rights Under Law.

Among 30 people expected to testify are S.C. House Speaker Bobby Harrell, R-Charleston; Lt. Gov. Glenn McConnell, R-Charleston; Marci Andino, executive director of the State Election Commission; Kevin Shwedo, executive director of the S.C. Department of Motor Vehicles; and Barbara Zia, head of the S.C. League of Women Voters.

Perez of the Justice Department will argue that white male S.C. legislators excluded their black counterparts from deliberations on the photo ID bill and ignored their concerns.

“African-American legislators in the (S.C.) House had no meaningful input,” Perez wrote in his brief. “Compromises struck with African-American senators were repeatedly gutted, as the provisions they sought to have included in the bill — acceptance of government employee IDs, exemptions for the elderly, and early voting — were stopped.”

The trial also will see dueling experts, each bringing reams of election, voting and demographic data.

The state’s star witness, University of Georgia political scientist Trey Hood, will testify that the photo ID law would produce “no legally disparate impact on minority voters.”

The Justice Department will call Charles Stewart, a political scientist at Massachusetts Institute of Technology, and Ted Arrington, a political science professor emeritus at UNC-Charlotte. Stewart will testify that the law would “impose disproportionate burdens on minority voters ... that do not currently exist under South Carolina law.” Arrington will testify that the photo ID law “was enacted with a racially discriminatory purpose.”

The intervening civil rights groups will call three scholars, among them Clemson University history professor Orville Vernon Burton, who will testify that the law is intended to suppress the strength of the African-American vote.

Also testifying will be several S.C. voters who will say the law would make it more difficult for them to cast ballots.

Based on its pretrial brief, South Carolina’s case rests heavily on a 2006 U.S. Supreme Court decision that upheld an Indiana voter ID law.

In that 6-3 ruling, Justice John Paul Stevens, who led the high court’s liberal wing until his 2010 retirement, said that law would burden only a small share of voters, burdens offset by Indiana’s need to prevent electoral fraud.

“Because Indiana’s cards are free, the inconvenience of going to the Bureau of Motor Vehicles, gathering required documents and posing for a photograph does not qualify as a substantial burden on most voters’ right to vote, or represent a significant increase over the usual burdens of voting,” Stevens wrote.

Clement noted South Carolina’s law partly was modeled on the Indiana law, providing provisional ballots to voters without photo IDs if they sign an affidavit.