As congressional Democrats consider how to respond to President Trump’s firing of FBI Director James Comey, what institutional procedures are available as part of their response?

This piece will bracket the question of what Democrats should be demanding from Republicans and instead focus on the set of tactics Democrats could use to attempt to extract concessions if they choose to do so. It will also focus on the Senate, since the minority party’s procedural rights are more extensive in the upper chamber and the Senate’s advice and consent responsibility opens up an additional avenue of influence. The Democrats have essentially three categories of options:

1. Obstructing Nominations

One logical option would be to obstruct of the president’s nominee to replace Comey as FBI director until Democrats’ demands are met. Deliberation on the nominee would begin in the Senate Judiciary Committee, which has jurisdiction over nominees to the Department of Justice. Under the committee’s rules, any member of the committee can request a one-week delay in consideration of the nomination, which would slow down the process. Members of the Senate’s minority party have availed themselves of this option on a number of high-profile nominees in recent years. Democrats, for example, delayed committee votes on Attorney General Jeff Sessions and Supreme Court Justice Neil Gorsuch earlier this year, while Republicans did the same for Justices Elena Kagan and Sonia Sotomayor during the Obama administration. These postponements are largely symbolic, though they could be useful if Democrats believe more time would give them a chance at getting some Republicans on board.

A second option would be for committee Democrats to deny their Republican counterparts the necessary quorum to approve a FBI director nominee. Under the committee’s rules, nine of the panel’s 20 members, including at least two members of the minority party, “shall constitute a quorum for the purposes of transacting business.” Preventing committee action by failing to show up is not unheard of in the Senate; Republicans on the Environment and Public Works Committee, for example, used the tactic in 2013 to protest the EPA administrator nominee. When Finance Committee Democrats deployed it in January against HHS Secretary Tom Price and Treasury Secretary Steven Mnuchin, however, the committee’s Republicans responded by voting to suspend the panel’s rules and report out the nominees in question. If Judiciary Committee Republicans are willing to make a similar move, the Democrats’ ability to pull a ‘disappearing quorum’ and obstruct without Republican help would be undermined.

Delaying the nomination by a week and denying a quorum are tactics Democrats could deploy unilaterally. If any Judiciary Committee Republicans were also skittish about Trump’s pick to be the FBI director and were willing to vote against him or her in committee, however, that could potentially derail the nomination. A 10-10 tie vote would prevent the nomination from being sent to the floor. The committee could, alternatively, report out the nominee with an unfavorable recommendation. It is unusual, though not entirely unheard of, for such nominees to come up for a vote on the floor of the Senate. Procedures exist for discharging nominations from committee, but doing so potentially requires the vote of three-fifths of the Senate at a key juncture; Democrats could obstruct such a vote.

If an FBI director nomination reaches the Senate floor, a simple majority of senators could invoke cloture and end debate on the nomination. With the tie-breaking vote of Vice President Pence available, at least three Republicans would have to defect and join Democrats in voting against the nominee for it to fail. As evidenced during the consideration of Trump’s cabinet nominees, however, Democrats can slow down the process by insisting that all 30 hours of post-cloture consideration allowed for under the Senate’s rules elapse before a vote on confirmation. In several cabinet cases, Democrats used this time to engage in extended, overnight “talk-a-thons” to make public their objections to the nominee in question.

If Democrats wanted to broaden their obstruction beyond the FBI director nomination, they could use the tactics described here against other nominees as well, though the rules for things like layover requests and quorum requirements vary across Senate committees. Without Republican help, they cannot prevent confirmation, but they can draw the process out.

2. Obstructing Legislation

Beyond delaying action on nominations, both to head the FBI and more generally, Democrats can also rely on their most conventional obstructive tactic: the legislative filibuster. Republicans hold 52 seats in the Senate, so ending debate on any piece of legislation not otherwise protected from a filibuster requires the support of at least eight Democratic senators. While much of the Senate’s early legislative agenda this year has involved filibuster-proof resolutions overturning Obama-era regulations, the time window for considering such bills has closed. In addition, Republicans’ next big legislative priority—health care—also enjoys procedural protections. For other items on the Senate’s agenda, the routinization of the filibuster in recent decades means that it is unlikely to be Democrats’ greatest source of leverage. The next round of “must pass” bills on which Democrats will have to deliver some votes—and thus might be able to extract concessions in exchange for their support—will not appear on the Senate’s agenda until September.

3. Obstructing the Routine Operations of the Senate

Beyond delaying action on nominations and legislation, Senate Democrats can also work to slow down and, in some cases, halt the ordinary conduct of the chamber’s business. This tactic involves objecting to unanimous consent requests, or unanimous agreements to waive temporarily certain Senate rules. Where even a single senator objects the request is denied. These unanimous consent requests and agreements are central to the management of the Senate, as they serve to expedite the business of the chamber. In some situations, an objection means precious floor time is spent actually carrying out whatever function the request would have waived. An objection to a request to waive the reading of an amendment, for example, means the text of the proposed provision must actually be read aloud on the floor. In other cases, such as with a request to allow committees to meet at certain times of day, an objection prevents something else (i.e., those hearings) from happening. And in yet other situations, like with a motion to enter executive session, objecting to a unanimous consent request means an actual vote is required on the question at hand. There are a range of other routine tasks the chamber usually completes by unanimous consent, all of which could be opposed as long as a single Democratic senator is on the floor to register the objection.

Unanimous consent agreements can also serve a second, more substantive purpose in the chamber: establishing the parameters of debate for a particular piece of legislation. Agreements of this type will specify, for example, how long debate will last, which amendments will be considered, and when a final vote will take place. In the absence of such an agreement, the Senate is left to rely on its regular rules and precedents, and doing so will generally consume more time. For example, a cloture motion does not “ripen” until one hour after the Senate convenes on the second day after it has been filed. When the Senate is under a time crunch, the majority leader may seek unanimous consent to hold a vote sooner. If a senator objects, however, all the time must elapse before the motion is voted on, again delaying progress.

It is worth noting that the list of tactics offered here is not exhaustive—the Senate is a complicated institution with many procedural quirks that the parties can exploit as necessary. They also vary in their likelihood of success. If the minority is attempting to gain some particular concession by holding up unrelated matters, it is at its most powerful when the majority really wants to do whatever is being obstructed, whether because time is pressing or because it addresses an important issue. Currently, the highest-profile items on the Senate’s agenda are Trump administration nominations to sub-cabinet positions, which, while important, do not necessarily generate the same sort of pressure as a major legislative priority.

Early reporting on the Democrats’ strategy suggests they may be leaning towards enlisting three Republicans to help them block confirmation on a new FBI director, but they have other tools at their disposal as well, should they want to use them.