Let’s say Democrats want to shut down the center in order to force a vote on one of their own proposals — for example, a bill to prevent the federal government from separating parents and children as they seek asylum at our nation’s borders. They can do it anytime they want. Let me explain.

In order for the Senate to do anything, there must be a sufficient number of members present. Article 1, Section 5 of the Constitution states:

a majority of each shall constitute a quorum to do business; but a smaller number may adjourn from day to day, and may be authorized to compel the attendance of absent members, in such manner, and under such penalties as each House may provide.

Other than quitting for the day or calling for others to come to the chamber, the Senate can do nothing without a majority of its members — 51 senators — participating in a vote. No bill can pass, no amendment can be decided on, no nominations can get approved.

At present, it would be extremely difficult for Republicans to provide a quorum with their own numbers. Their majority stands at 51-49, with Sen. John McCain on extended leave in Arizona. If no Democrat participates, the Republicans cannot provide a quorum.* In the month of June, there have been an average of 1.8 Republican absences across 18 roll call votes, so even if McCain returned to the Senate, the majority would struggle to consistently provide a floor majority.

This provides Senate Democrats with real leverage. If they refuse to participate in roll call votes, the Senate will come to a halt for lack of a quorum.

This tactic would put pressure on every Republican to be near the chamber whenever the Senate is in session and Democrats are able to force a vote on any procedural question. If Republicans are busy in the morning raising money and holding committee meetings, Democrats can force them into the Senate chamber and keep them there. The same is true during peak fundraising time in the early evening, or if the Senate is in session on Friday, or during the month of August. Meanwhile, vulnerable Senate Democrats will be doing their part by staying out of the Senate chamber and using their time more productively.

This would be a confrontational tactic; the Senate Democrats would probably only use it to make a fundamental point about the Senate’s role in American democracy. And that point should be that the Senate must be an institution where there is free and open debate so the majority can rule. As James Wallner argues, current Majority Leader Mitch McConnell’s strategy has long been to avoid any issue that harms the majority party’s image or the electoral prospects of Republican senators. Wallner states:

For McConnell, winning elections is necessary to control the Senate’s means of production: its committee chairs, leadership positions, and votes...Winning elections to maintain (or regain) a majority is therefore the ultimate end of his efforts. He is unwilling to tolerate freewheeling debates à la Mansfield precisely because these can’t be controlled. And while the Senate has proved incapable of accomplishing very much with McConnell’s approach ... the majority leader can at least keep divisions within his party under wraps and thus present the electorate with a unified — and inoffensive — message during elections.

“Mansfield” here is Montana Democrat Mike Mansfield, who served as Senate majority leader from 1961 to 1977 and managed the Senate with the philosophy that every senator is equal and his job was to facilitate their will. McConnell’s mantra, on the other hand, is, “I’m the one who decides what we take to the floor. That’s my responsibility as the majority leader.”

At present, there are several critical bills kept from the Senate floor by McConnell’s policy:

A bill to protect special counsel Robert Mueller’s investigation from presidential influence, reported out of the Senate Judiciary Committee by a 14-7 majority.

A bill to give Congress final authority over tariffs imposed to protect “national security.”

A bill to reinstate the Deferred Action for Childhood Arrivals program, without the debate restrictions imposed by McConnell in February.

A bill to prevent family separation at the border, the Keep Families Together Act, which currently has united Democratic support.

The current uproar over Trump’s policy of separating families seeking asylum could provide Democrats a justification for shutting down the Senate until McConnell loosens his grip on the floor agenda. This is especially true since Trump has falsely blamed Democrats for this policy. And any Republican opposed to Trump’s family separation policy can tacitly aid the protest simply by avoiding the Senate floor during votes.

*I’m uncertain whether Vice President Mike Pence could contribute a 51st vote toward a quorum. The Senate precedents on quorums do not mention this question.