From Fox News:

There are ways around this. Most notably, the Senate can vote on a discharge resolution that would remove the responsibility of considering the Barrett nomination from the committee, allowing Senate Majority Leader Mitch McConnell, R-Ky., to call the nomination for a full vote. The committee itself could also change its rules to get rid of the requirement that two Democrats be present, James Wallner, a senior resident fellow for governance at the R Street Institute told Fox News.

“The key for Democrats is to make Republicans’ doing so as painful as possible,” Wallner said about the move to force Republicans to change the committee rules, as well as other procedural moves they could try. “Schumer’s announcement that Democrats have already decided not to attend a committee markup lessens any leverage Democrats can hope to gain in the larger debate by forcing Republicans to change the rules to get Barrett to the floor.”