Senator Mitch McConnell recently announced that he intends to eliminate much of the August recess so that the Senate has more time to confirm nominees and pass funding legislation. Senate Republicans want this extra time because even if Republicans have the votes (i.e., 60 for legislation and 50 for nominations), they still need 30 hours of floor time to overcome a Democratic filibuster.
Although Democrats have publicly made positive comments regarding eliminating the recess, they likely privately oppose the change as a political stunt that (1) prevents vulnerable Democratic incumbents from campaigning for reelection and (2) provides more time for Republicans to confirm nominees. If Democrats wanted to publicly support eliminating the recess, but make the process as difficult as possible for Republicans, they could aggressively use (or threaten to use) the quorum rule.
To be in session, the Senate must have a quorum of 51 senators on the Senate floor. In practice, a quorum is not usually present. Instead of listening to other senators speak to the C-Span cameras, senators usually spend their time outside the Senate floor (but still near the Capitol) going to hearings, marking up legislation, and meeting with constituents. Even though a quorum of senators is not present on the floor, the Senate assumes that a quorum is present. However, any senator may request a quorum call, and if the call does not show a quorum present, “no debate nor motion, except to adjourn, or to recess pursuant to a previous order entered by unanimous consent, shall be in order.” By practice, senators do not make these type of quorum calls because (1) they also want to spend their time off the floor doing pressing work and (2) do not want to be “that jerk” who required everybody to drop what they are doing to come to the Senate floor.
If Senate Democrats see eliminating the recess as a political stunt, they could break with general practice and require these quorum calls. A quorum call would effectively require every Republican senator to come immediately to the Senate floor. With Senator John McCain too sick to vote, Republicans effectively only have 50 seats. If every Democrat refused to show up, Republicans would not have a quorum. However, Republicans effectively only need 50 Republican senators present because unanimous consent rules (i.e., the Senate can violate its procedures if nobody objects) require at least one Democrat to be present at all times. Without a Democrat present, Republican senators could move without objection to set aside the quorum call. Thus, Democrats would need to provide at least one senator to ensure that the quorum call continues.
Effectively, the threat of a Democratic quorum call would require that any time Senator McConnell wants the Senate to be in session, every Republican senator must be near the Capitol. This requirement could prove troublesome if a Republican senator has already scheduled an event that the senator does not want to miss or the Senate conducts floor time after a Republican senator leaves for the night. Even if Republicans could produce a quorum with some delay (e.g., waking a Republican senator or arresting a Democratic senator), the time that it took Republicans to produce the quorum would not count as floor time for overcoming the 30-hour waiting period.
Alternatively, Democratic senators would have the freedom to leave town during large periods of the recess because no votes would be taking place during the 30 hours the Senate would use to overcome a filibuster. Thus, even though Democrats cannot prevent Senator McConnell from eliminating the August recess, they could ensure that the hardships of eliminating the August recess falls disproportionately on Republican senators.