In 1963, when the newly sworn-in Lyndon Baines Johnson was advised against using his limited political capital on the controversial issue of civil and voting rights for Black Americans, he responded: “Well, what the hell’s the presidency for?”

America is again approaching a crucial decision-point on the most fundamental right of all in a democracy – the right to vote. The result will either be the biggest advance since LBJ’s landmark Civil Rights and Voting Rights Acts of 1964 and 1965, or the biggest setback since the end of Reconstruction and start of Jim Crow in the 1870s.

The decisive factor will be President Joe Biden.

On one side are Republican lawmakers who now control most state legislatures and are using false claims of election fraud to enact an avalanche of voting restrictions on everything from early voting and voting by mail to voter IDs. They also plan to gerrymander their way back to a House majority.

After losing the Senate and the presidency, they’re determined to win back power by rigging the rules againstlikely Democrats, disproportionately Black and brown voters. As a lawyer for the Arizona Republican party put it baldly before the Supreme Court, without such restrictions Republicans are “at a competitive disadvantage relative to Democrats.”

On the other side are congressional Democrats advancing the most significant democracy reform legislation since Lyndon Johnson’s civil rights and voting rights laws – a sprawling 791-page “For the People Act” establishing national standards for federal elections.

The proposed law mandates automatic registration of new voters, voting by mail, and at least 15 days of early voting. It bans restrictive voter ID laws and purges of voter rolls – changes that studies suggest would increase voter participation, especially by racial minorities. It also requires that congressional redistricting be done by independent commissions and creates a system of public financing for congressional campaigns.

The legislation sailed through the House last week on a party-line vote. The showdown will occur in the U.S. Senate, where Republicans are determined to kill it. Although Democrats now possess a razor-thin majority, the bill doesn’t stand a chance unless Democrats can overcome two big obstacles.

The first is the filibuster, requiring 60 votes to pass regular legislation. Notably, the filibuster is not in the Constitution and not even in law. It’s a rule that has historically been used against civil rights and voting rights bills, as it was in the 1960s when LBJ narrowly overcame it.

Democrats can – and must — finally end it now, with their 51-vote majority.

But if they try, they face a second obstacle. Two Democratic senators – West Virginia’s Joe Manchin and Arizona’s Kyrsten Sinema – have said they won’t vote to end the filibuster, presumably because they want to preserve their centrist image and appeal to Republican voters in their states. A few other Democratic senators are lukewarm to the idea.

Well, I’m sorry. The stakes are too high. If Democrats fail to enact the “For the People Act,” Republicans will send voting rights into retreat for decades. There’s no excuse for Manchin and Sinema or any other Senate Democrat letting Republicans pull America backwards towards Jim Crow.

And no reason Biden should let them. It’s time for him to assert the kind of leadership LBJ asserted more than a half-century ago on civil and voting rights.

Johnson used every tool at his disposal, described by journalist Mary McGrory as “an incredible, potent mixture of persuasion, badgering, flattery, threats, reminders of past favors and future advantages.”

He warned Georgia Senator Richard Russell, a dedicated segregationist, “Dick, I love you and I owe you. But….I’m going to run over you if you challenge me on this civil-rights bill.” He demanded his allies join him in pressuring holdouts. Senator Hubert Humphrey later recalled “the president grabbed me by my shoulder and damn near broke my arm.”

Historians say Johnson’s importuning, bribing, and threatening may have shifted the votes of close to a dozen senators, breaking the longest filibuster in Senate history and clearing the way for passage of the Civil Rights Act of 1964 and Voting Rights Act of 1965.

We are once again at a crucial juncture for civil rights and voting rights that could shape America for the next half century or more. Joe Biden is not LBJ, and the times are different from the mid-1960s. But the stakes are as high.

Biden must wield the power of the presidency to make senators fall in line with the larger goals of the nation. Otherwise, as LBJ asked, “what the hell’s the presidency for?”