Attorney General Eric Holder Jr. called Tuesday's gutting of a key provision of the Voting Rights Act by the U.S. Supreme Court "a serious and unnecessary setback," but he said the department will press on in the enforcement of voting rights laws.

Holder and President Barack Obama called on Congress to plug any holes in the voting rights law in the wake of the Supreme Court decision in Shelby County v. Holder, which voided the formula that's used to determine which jurisdictions require greater scrutiny before making any voting-related changes to local law.

A key U.S. senator pledged to introduce legislation to restore the law, but experts doubted that any movement on the issue will happen in this congressional session.

"This is a radically different Congress than the one that passed the last extension," said Norman Ornstein of the American Enterprise Institute. "I think the odds of the short term are very, very slim, and I think the Supreme Court knew that."

Holder, delivering a statement at Main Justice two hours after the Supreme Court ruling, said the Justice Department will "continue to carefully monitor jurisdictions around the country for voting changes that may hamper voting rights." Holder said he was "deeply disappointed" by the high court decision striking Section 4 of the Voting Rights Act.

"Let me be very clear: we will not hesitate to take swift enforcement action—using every legal tool that remains available to us—against any jurisdiction that seeks to take advantage of the Supreme Court’s ruling by hindering eligible citizens' full and free exercise of the franchise," Holder said.

Holder, who often hails his protection of voting and civil rights as one of his proudest achievements at the helm of the Justice Department, did not take any questions from reporters. Assistant Attorney General Thomas Perez, who has led the department's Civil Rights Division since 2009, did not join Holder on the stage.

The Justice Department has won Voting Rights Act cases over the last 18 months, which Holder called a sign that "the need for a vital—and intact—Voting Rights Act remains clear."

Federal courts cited the value of the law in blocking the Texas congressional redistricting map because it discriminated against Latino voters, and the value in prompting South Carolina to no longer disproportionately harm black voters, Holder said.

"Without the Section 4 coverage formula, neither of these discriminatory voting changes would have been subject to review and both could have been implemented immediately," Holder told reporters.

The Justice Department, Holder said, will work with Congress to formulate legislative proposals to address voting rights discrimination, "because, on their own, existing statutes cannot totally fill the void left by today's Supreme Court ruling."

Obama separately issued a statement calling on Congress to pass legislation to help efforts to end voting discrimination and to ensure equal access to polls.

"For nearly 50 years, the Voting Rights Act—enacted and repeatedly renewed by wide bipartisan majorities in Congress—has helped secure the right to vote for millions of Americans," Obama said. "Today's decision invalidating one of its core provisions upsets decades of well-established practices that help make sure voting is fair, especially in places where voting discrimination has been historically prevalent."

Senator Patrick Leahy (D-Vt.), chairman of the Senate Judiciary Committee, said in a statement that he intends "to take immediate action to ensure that we will have a strong and reconstituted Voting Rights Act that protects against racial discrimination in voting."

Congress, Leahy said, reauthorized the Voting Rights Act and it was signed into law by a Republican president in 2006. Leahy described it as "a thorough and bipartisan process in which Congress overwhelmingly determined that the law was still vital to protecting minority voting rights and that the coverage formula determining the jurisdictions to be covered was still applicable."

"Despite this sound record, and the weight of history, a narrow majority has decided today to substitute its own judgment over the exhaustive legislative findings of Congress," Leahy said in the statement.

There was not a lot of optimism that a partisan Congress would make a fix. The reason, Ornstein said, is that the Congress is not only more partisan now, but it is "tribal." Any effort to change this now will either flounder in a filibuster in the Senate or have no action in the House Judiciary Committee, Ornstein said.

Senator Chuck Schumer (D-N.Y.) conveyed skepticism in a statement issued after the Supreme Court's ruling.

"As long as Republicans have a majority in the House and Democrats don't have 60 votes in the Senate, there will be no preclearance. It is confounding that after decades of progress on voting rights, which have become part of the American fabric, the Supreme Court would tear it asunder," Schumer said.

Senator Chuck Grassley (R-Iowa), the judiciary committee’s ranking member, said in a statement that Tuesday’s decision still protects both the anti-discrimination provisions of the Voting Rights Act and the Tenth Amendment.

“Most importantly, the Supreme Court ensured that discrimination remains unlawful, but, the court said that preclearance of voting changes cannot be based on election laws and voter registration and turnout as they existed in the 1960s and early 1970s,” Grassley said. “No longer will any Justice Department be able to misuse the Voting Rights Act concerning such common sense measures as voter identification laws.”

The effort to repair the law is expected to have a Republican counterpart on the other side. Representative James Sensenbrenner (R-Wis.) was a leader in passing the reauthorization in 2006. Sensenbrenner called Section 5 an important part of the Voting Rights Act, in an interview in March with The Huffington Post.

"If it's struck down and fixable, Congress has the obligation to fix it," Sensenbrenner said then. He had not issued a reaction Tuesday to the high court decision in Shelby.

But there are also signs of opposition in the House. Rep. Jeff Duncan (R-S.C.) said in a written statement that the ruling was a win for fairness and the rule of law.

"The preclearance requirement forced South Carolina to spend millions of dollars to defend a photo identification requirement for voting that had already been ruled constitutional by the US Supreme Court," Duncan said. "The court's ruling will hopefully end the practice of treating states differently and recognizes that we live in 2013, not the 1960s."

Todd Ruger can be reached at truger@alm.com.