One Donald Trump ally — Stephen K. Bannon — is staring at potential jail time for not sharing with Congress what he knows about the extent to which the Jan. 6 attack on the Capitol was premeditated.

Another, former White House chief of staff Mark Meadows, is doing everything he can to avoid such a fate while also not cooperating with the special House committee investigating the attack on what he knows about plans behind it. He’s refused to talk to the committee, and he’s actually suing it to avoid having to cooperate.

Other Trump allies are invoking the Fifth Amendment to avoid testifying, which allows someone to avoid giving self-incriminating testimony but is not an admission of guilt. Now, the committee wants to get documents from and potentially talk to a sitting member of Congress, Rep. Scott Perry (R-Pa.).

So what can lawmakers do to enforce the subpoenas or punish the holdouts? Congress has a few options, but its ability to enforce them is weak in some ways. The toughest one is trying to jail people for not complying with a subpoena, and Bannon may not be the only person facing such a threat.

Here’s the latest in the battle between Trump’s inner circle and the congressional committee trying to find out exactly what the former president knew about the deadly insurrection and when he knew it.

First, Congress votes to hold someone who doesn’t comply in contempt of Congress.

While that sounds intense, it’s a threat that’s been watered down as it happens with increasing frequency. Attorneys general of the previous two White Houses have been held in contempt of Congress by Houses controlled by the opposite party, and nothing happened to them. A contempt vote is becoming the equivalent of a slap on the wrist.

But the Jan. 6 committee is using these contempt charges as the first step to jailing people who aren’t cooperating. First, the committee votes to hold the person in contempt for ignoring their subpoenas. Then, the full House votes (usually along party lines) to hold that person in contempt. They did this with Bannon and, more recently, Meadows.

Congress often stops there, but it doesn’t have to.

Lawmakers can take that contempt citation and hand it over to the Justice Department and ask the government to prosecute the person ignoring the subpoena. They already did this with Bannon. They are planning to do this with Meadows, who stopped cooperating after handing over emails and texts to the committee.

But they’re holding off on this for Jeffrey Clark, a top Justice Department official under Trump who pushed false fraud claims, to give him another chance to testify.

Worst-case scenario, these Trump allies could face jail time of up to a year. A grand jury already indicted Bannon, and he faces a trial this summer. Meadows could be next.

Congress can sue the person and demand they comply

The courts have long upheld Congress’s right to use this power, though Trump fought the Democratic House’s various investigations into him every step of the way. House Democrats spent two years tied up in court trying to get former White House counsel Donald McGahn to testify about the Russia investigation; he eventually did this summer.

Most recently, a case from Congress to get Trump’s tax records went all the way to the Supreme Court and back down. A judge ruled that lawmakers can have some — but not all — of the records. Congress got those tax records years after it initially requested them.

So far, the committee hasn’t used this option, in part because it doesn’t have a lot of time. It is trying to finish its investigation before the next midterm elections, in November, when control of Congress could change hands to Republicans, who could disband the investigation.

Or it could jail them in the halls of Congress

Yes, Congress can send out its sergeant-at-arms to arrest people who ignore its subpoenas. It’s a dormant power that Democrats briefly talked about using in the Trump era when they held Attorney General William P. Barr in contempt.

But Congress doesn’t have a jail. A century or so ago, it held people in empty committee rooms for a few days, or it asked the D.C. jail to hold them.

As dramatic as this sounds, this fourth option is something lawmakers on the Jan. 6 committee are at least talking about. “This is a matter of the utmost seriousness, and we need to consider the full panoply of enforcement sanctions available to us,” said Rep. Jamie B. Raskin (D-Md.) earlier this year.

How Trump aides can try to defend themselves

There are a few legal exceptions to complying with a subpoena, most notably claiming executive privilege — a loose protection for the president and top White House aides as they make tough decisions while governing, without fearing that those private conversations will be scrutinized by Congress.

Trump isn’t president anymore, but he’s trying to claim executive privilege to stop the committee from getting more information about his internal conversations around Jan. 6. He isn’t actually receiving any subpoenas, but the committee has asked the National Archives to hand over Trump’s records. President Biden has agreed to release the records. Trump can try to stop that by going to court, where he has a good chance to at least delay the records requests.

Trump allies who don’t want to talk to the committee are trying to assert executive privilege too, to varying degrees of success.

Meadows has the strongest case to claim executive privilege, since he was a top official in the White House at the time. He’s doing that and he’s also suing the committee to avoid talking to them.

Meadows argues he was cooperating with the committee — he handed over private emails and text messages — but lawmakers kept wanting to question him about things that are off-limits. The committee says they want to ask him about things he’s already shared with them.

Legal experts say the committee probably has the upper hand in this legal fight. There’s a “speech and debate clause” in the Constitution that protects lawmakers from lawsuits for doing their jobs. But Meadows can drag things out and hope his case gets mired in legal fights that make it harder for officials to prosecute him, as compared with Bannon, who just thumbed his nose at the committee entirely.

“As a strategy to keep himself out of jail, this will probably work,” said Mike Stern, a former lawyer for Congress.

Other Trump allies are trying something more straightforward. Clark and Trump lawyer John Eastman are planning to go before the committee and plead the Fifth. This is a well-established way to avoid testifying, Stern said. The committee could offer them immunity for their testimony and see whether they’d accept. If not, they could continue to pursue their contempt charges and try to put these people in jail.

Members of Congress like Perry could try to fight the subpoenas by arguing they are politically motivated, but “no court has recognized that as a reason in itself,” said Stanley Brand, a lawyer who is now representing former deputy White House chief of staff Dan Scavino.

So while Congress’s enforcement power of subpoenas has its weak spots, if it wants to really ramp up the pressure, there aren’t a lot of ways around avoiding a subpoena, other than going to jail.

This has been updated with the latest news.