Senate Majority Leader Charles E. Schumer plans to push ahead with debate and consideration of changing the Senate’s filibuster rules by Martin Luther King Jr. Day, if voting rights legislation continues to be blocked.

“We must ask ourselves: if the right to vote is the cornerstone of our democracy, then how can we in good conscience allow for a situation in which the Republican Party can debate and pass voter suppression laws at the State level with only a simple majority vote, but not allow the United States Senate to do the same,” Schumer, a New York Democrat, wrote in a "Dear Colleague" letter. “We must adapt. The Senate must evolve, like it has many times before.”

Schumer said that the Senate Democratic caucus planned to use this week’s anniversary of the Jan. 6 Capitol insurrection to help further the case for advancing new voting rights legislation, citing the “big lie” espoused by former President Donald Trump and his supporters that he somehow won the 2020 election.

“Specifically, as we honor the brave Capitol police officers who defended us from those motivated by the Big Lie who tried to undo a fair and free election, Senate Democrats will continue to make the case for passing voting rights legislation to counter the Republican voter suppression and election nullification laws with the same anti-democratic motives born out of the Big Lie,” Schumer wrote.

A Senate substitute version of a House-passed bill to restore parts of the Voting Rights Act that were struck down in a 2013 Supreme Court decision was crafted in part by Sen. Joe Manchin III, D-W. Va., and the entire caucus also backs a narrower election and campaign finance law rewrite than what passed the House.

In mid-December, Senate Democrats coalesced behind the idea of pushing their voting rights legislation ahead of a budget reconciliation measure that would implement much of President Joe Biden’s domestic spending agenda. Manchin has expressed opposition to the most recent version of that package.

Last month, Biden said that he would support carving out an exception to the Senate’s 60-vote requirement to limit debate on legislation if that is what is required to overcome obstacles to passing such a bill.

“I don’t think we may have to go that far,” Biden said in an ABC News interview, ”But I would be if that’s, if it’s — the only thing standing between getting voting rights legislation passed and not getting passed is the filibuster, I support making the exception of voting rights for the filibuster.”

Under regular order, a two-thirds vote of the Senate would be required to get past a filibuster to change the rules themselves. But, as has been done in the past, a simple majority could change Senate precedents.

Senate Minority Leader Mitch McConnell, R-Ky., who has long made campaign finance law one of his top priorities, has continued to say that the federal government shouldn’t play an increased role in setting local election regulations.

“Each state ought to craft its own election rules, with one exception, the Voting Rights Act. It’s against the law to discriminate against people in the voting process on the basis of race. No one is doing that. If they do, it’s against the law and can be prosecuted,” McConnell said last month on Hugh Hewitt’s radio show. “There is no rationale for the federal takeover of elections, other than Democrats want to make it easier to cheat, frankly. They want to make sure states can’t have photo ID at the polls, they want to guarantee that states can have what’s called ballot harvesting. That’s where you run around picking up other people’s votes for them and turn them in.”

Members of the Democratic caucus continued to discuss potential rules changes over the holiday recess, according to a Democratic aide. Those talks are likely to lead to a debate on the floor ahead of the Jan. 17 holiday to honor King.