President Biden will speak Tuesday to align himself with Senate Democrats and endorse altering chamber rules to advance important voting rights legislation, The Associated Press reports. But what exactly do upper chamber Democrats want, and what rules changes are they talking about?

At the moment, Senate Democrats aren’t looking to completely eliminate the 60-vote threshold — also known as the filibuster — that’s required to pass most legislation, Politico reports. Rather, they’re mulling voting along party lines to change chamber rules, a process known as going “nuclear,” to pass election and voting reform bills. In a 50-50 Senate, however, Democrats will need every members’ vote for any tweaks to succeed. 

As one option, Democrats have discussed a return to a “talking filibuster,” under which a senator from the minority party can talk for as long as they want to block a bill, Politico writes. Debate continues until 60 senators vote for it to end (similar to current rules), or the minority party “leaves a vacancy on the floor — at which point the majority party can move to final passage of the bill, requiring only a simple majority vote.”

Democrats are also considering lowering the required votes to start debate on a bill from 60 to 50, which could be done in conjunction with the talking filibuster, notes Politico. 

Additionally, though unlikely, the party has discussed implementing a filibuster “carveout” allowing a one-time exception to pass voting legislation with a simple majority, as well as altering the number of senators needed to end a filibuster from 60 to three-fifths of those actually voting that day.

“In other words,” explains Politico, “if 80 senators show up for a specific vote, the Senate would only need 48 members to vote to end a filibuster instead of 60.”

Another option considers requiring 41 minority party votes to continue filibustering, or else debate would automatically end.