Less than a month after the Supreme Court struck down a key provision in the landmark 1965 Voting Rights Act, Congress has kicked off a long, arduous attempt to rewrite the federal government’s most potent tool against voting discrimination.

The Senate Judiciary Committee on Wednesday held the first of what could be dozens of congressional hearings to determine which states, if any, need federal oversight of their elections after the high court rejected the previous list.

A House judiciary subcommittee is scheduled to hold a similar hearing Thursday.

The Senate hearing didn’t produce potential solutions, instead serving as a warm-up to a congressional debate that could last years.

“Voting discrimination still exists; no one doubts that,” said Judiciary Committee Chairman Patrick Leahy, D-Vt. “The Supreme Court has called on Congress to come together to update the Voting Rights Act to meet current conditions, and it is up to us to meet that challenge.”

The panel’s key witness, Rep. John Lewis, D-Ga., a veteran of the Civil Rights movement in the 1960s, decried the high court’s decision, calling the law “the most powerful nonviolent tool we have.”

“The day of the [Supreme Court’s] Voting Rights Act decision broke my heart. It made me cry,” Lewis said. “We are a better country, a better people, because of the Voting Rights Act.”

Rep. James Sensenbrenner, R-Wisc., told the panel the law was the “most successful of all the important Civil Rights acts passed since the 1950s.”

“We cannot afford to lose it now,” said the lawmaker, who played a key role in reauthorizing the law the last time it came before Congress in 2006, when he was chairman of the House Judiciary Committee.

The Supreme Court’s 5-4 ruling, while leaving most of the Voting Rights Act intact, threw out key rules that required all or parts of 16 states, mostly in the South, to seek approval from the Justice Department or a federal court before making changes in the way they hold elections.

The high court didn’t invalidate the constitutionality of the advance approval, known as the “preclearance” requirement. But it rejected the formula passed by Congress to determine which states and jurisdictions deserve extra scrutiny, saying it failed to take into account changing circumstances in the South. The move essentially neutered the law’s central tenet.

The court left it up to Congress to draft new voting guidelines to ensure that states and cities with a history of voting discrimination properly following the Voting Rights Act.

The law traditionally has attracted wide bipartisan support, as seven years ago the Senate unanimously reauthorized it while the House approved it 390-33.  But with a deeply divided Congress, a consensus on new rules will be difficult.

And one of those lawmakers who rejected the law in 2006, Rep. Trent Franks, R-Ariz., now chairs the House Judiciary Subcommittee on the Constitution and Civil Justice, which is holding Thursday’s voting rights hearing in the chamber. The scenario has Voting Rights Act supporters fearing Franks will derail efforts to update the law.

Franks suggested to Politico last month that conservatives mostly remained silent in the wake of the court’s decision because they wanted to avoid being labeled as insensitive or even racist.

”In this day and age, no matter what argument one makes, even if it’s based on verifiable principle or the sincerest intention for the most noble purpose, it is often relegated to hate speech or something along those lines,” he told the publication. “Those who can’t debate the issue on its merits often resort to calling into question the motives of everyone who would advocate a particular position.”