In the absence of McCarthy reaching out to make a deal with them for rules changes or other concessions, Democrats in the House are reportedly united in a decision NOT to help him stay in the Speaker's seat. This means that the odds of McCarthy losing that seat today, while not certain, are quite high. 

This would also paralyze the House (with just weeks until the next government shutdown deadline) until a new Speaker is in place -- no other House business can proceed. 

As you may recall, McCarthy required 15 ballots over 4 days to become Speaker originally, the most ballots needed for a Speaker since before the Civil War.