Democrats on the House Judiciary Committee voted to hold Attorney General Barr in contempt of Congress, one of the most severe congressional actions. Here’s what the historic move means.

Democrats on the House Judiciary Committee voted Wednesday to hold Attorney General William Barr in contempt of Congress because the Department of Justice has also not complied with a subpoena for a full, unredacted version of the special counsel report submitted to Barr from former FBI Director Robert Mueller.

The move came after Attorney General William Barr declined to appear before the House Judiciary Committee on Thursday, which infuriated many committee Democrats.

Read more: House hearing on Mueller report devolves into a bizarre shouting match after Attorney General Barr refuses to show up

But the vote is a bit more complicated than that, as being held in contempt is a very rare, very serious charge.

Being held in contempt of Congress is very serious

Contempt of Congress is meant for individuals who refuse to either testify or provide documents and other materials to various congressional committees. This usually happens after said individual refuses to comply with a subpoena.

The punishments that go along with being held in contempt of Congress can include a criminal referral to a US attorney, which can result in severe punishments maxing out at either fines of up to $100,000 or one year in prison.

Congress has extensive power when it comes to government oversight, meaning they are well within their legal rights to compel individuals and documents from other areas of government. The Department of Justice only allowing lawmakers to view a redacted version of the Mueller report has led many Democrats to demand a full, untouched copy. There are other areas where the Democratic-controlled House is squabbling with the Trump administration, like the ongoing request for President Donald Trump’s tax returns.

Read more: Democrats are getting ready to ramp up their fight to get Trump’s tax returns – and it could get ugly

As for Barr’s refusal to testify, that invite was entirely voluntary. When committee Democrats decided they wanted to extend the hearing with supplemental questioning from committee counsel and staff – not just lawmakers – Barr informed them he would not be showing up for the marathon hearing.

This means that while Barr severely angered Democrats, he would likely have to wait for a subpoena to refuse before being held in contempt as it relates to him refusing to show up.

Executive branch officials have been held in contempt before, though it is rare

During the Barack Obama administration in 2012, the then-Republican-controlled House of Representatives voted to hold Attorney General Eric Holder in contempt of Congress for refusing to hand over materials relating to the ATF gun walking scandal known as “Fast and Furious.”

The contempt vote against Holder received bipartisan support, with several Democrats also joining in to back a criminal contempt referral. Ultimately, a federal judge passed on holding Holder in contempt in 2014, helping the former DOJ chief avoid potential punishment.

Before Holder, onlya couple dozen individuals have been held in contempt of Congress. The first contempt case was in 1795, when two men named Robert Randall and Charles Whitney attempted to bribe members of Congress.

Read more: Treasury Secretary Steven Mnuchin and the IRS blew through another deadline to turn over Trump’s tax returns

Other examples of contempt have been slapped on individuals for bribery attempts, as well as one instance for a libelous newspaper editor who refused to appear before the Senate in the early 1800s.

The process is lengthy and often results in no severe penalties for the subject being held in contempt. But Congress still has a host of other options they can pursue if they feel compelled. This could include bringing lawsuits against the Trump administration.

Another method lawmakers could use would be to pursue impeachment of Barr or other officials willing to comply. During the Obama administration, House Republicans repeatedly attempted to pursue the impeachment of then-IRS Commissioner John Koskinen, but ultimately failed.