"If you want to make it a little more painful, just let her stand there and talk, I'll be ready to see what we can," Manchin told Todd.
What Manchin is talking about is a proposed reversal of the filibuster rules, which requires 60 votes (currently) to end the Senate "debate" and move most Senate bills forward so that Senators want more debates to actually make the debate happen perform. This is called "Talking Filibuster" and is the type of filibuster portrayed in the famous Jimmy Stewart film "Mr. Smith Goes to Washington". A lone Senator or group of like-minded Senators will chat for as long as they can to block all other Senate business and stall work to prevent a vote from taking place. But that's not the current incarnation of the Senate's filibuster rules. In the current Senate, filibuster is the use of Senate rules that require 60 votes to move to each new phase of a bill, from the motion to change the reconciliation process. Each invocation requires a cloture vote scheduled two days later and an additional 30 hours of debate afterwards. This makes it easy for the minority to turn proposed legislation into a semi-infinite process that threatens to consume large chunks of the legislative calendar.
This is the version in use today, but it doesn't have to be. The Senate has changed the filibuster rules repeatedly in the past, each time in response to perceived abuses of the system, and can change them again by a simple majority. Over the past few decades, the application of the 60-vote rule to Stonewall legislation has shifted from a relative weirdness to an everyday occurrence, and could once again lead the Senate to tweak the rule to prevent its now perpetual abuse.
That Manchin suggests (during several interviews) that the filibuster rules could actually be adjusted to "make it a bit more painful", and in particular his suggestion that a return to the talking filibuster might be the pain required, is a change from that Manchin's usual unwavering support for the filibuster as a necessary tool for the Senate minority, but Manchin also insisted that he would continue to defend the 60-vote threshold.
This means that Senator Kyrsten Sinema remains the only Democrat who speaks out against all filibuster changes – although many of the other Democratic Senators themselves are cautious in their theoretical support. Killing the modern day "filibuster" for good would still be a tough task, but Republicans' use of the filibuster to block new proposed protections of voting rights while a wave of state bills attempt to reload old Jim Crow laws, criminalizing black voter turnout efforts are putting tremendous pressure on Democratic senators to persevere.