President Trump. (Manuel Balce Ceneta/AP)

This post has been updated with the latest news.

President Trump is systematically trying to block and undercut 20 investigations by House Democrats related to him, forcing Congress to take extraordinary measures to get its information — such as considering holding as many as three current and former Trump administration officials in contempt of Congress and taking them to court to enforce subpoenas.

These standoffs get at the heart of the definition of American democracy: one branch’s ability to check the other. Here is the latest on eight battles to watch.

On Russia

1. Getting the unredacted Mueller report: House Democrats want all members of Congress to see the full report by now-former special counsel Robert S. Mueller III. Attorney General William P. Barr refused to hand it over, so the Judiciary Committee voted to hold Barr in contempt of Congress, making Barr just the second sitting attorney general to be found in contempt of Congress. On Tuesday, the full House voted to allow the Judiciary Committee to take Barr to court to enforce a subpoena against him.

How this could escalate even more: But this actually just de-escalated a bit. Barr’s Justice Department came to an agreement with the Judiciary and the Intelligence committees to let them see a number of documents from the underlying Mueller report. House Judiciary Chairman Jerrold Nadler (D-N.Y.) described the documents as “key evidence” in whether Trump obstructed justice. It’s a start to getting the full Mueller report, Democrats hope.

2. Talking to Trump’s former White House counsel: The House committee that could launch impeachment proceedings subpoenaed one of the key players in the Mueller investigation, former White House counsel Donald McGahn. But in May, McGahn, under pressure from Trump, didn’t show. Trump also asserted executive privilege over his conversations with McGahn. Some legal experts argue that Trump lost his ability to exert executive privilege the day he decided not to use it when McGahn (and other aides) testified to Mueller.

The nameplate of former White House counsel Donald McGahn, who was scheduled to appear at a House Judiciary Committee hearing June 4. (Jonathan Ernst/Reuters)

How this could escalate: The House voted Tuesday to allow the Judiciary Committee to take McGahn to court to enforce its subpoena. Nadler has not ruled out voting to hold McGahn in contempt, either. Just like with the contempt vote on Barr, it’s a symbolic move — no one thinks the Justice Department under Trump would jail the president’s former White House lawyer. But it’s a serious escalation.

3. Getting Mueller to testify: Mueller has said he doesn’t want to testify to Congress; that his 400-page report about Russia and Trump is testimony enough. But Democrats want him in the hot seat, if only for the theatrics it would provide.

How this could escalate: Nadler hasn’t ruled out issuing a subpoena to force Mueller to talk. Unlike the Trump officials who have ignored subpoenas, the working theory on Capitol Hill is that Mueller would reluctantly comply with one.

On Trump’s finances

4. Did Trump inflate his assets?: Trump sued a member of Congress and Trump’s own accounting firm to try to prevent that firm from handing over a decade’s worth of his financial statements. The House Oversight Committee is investigating whether Trump inflated his assets or deflated them to get loans or avoid real estate taxes — which could constitute possible bank fraud. He lost the first round after a judge expressed “astonishment” at his team’s legal argument.

How this could escalate: The accounting firm is willing to hand over the documents. But could the ensuing appeals fight take so long that Trump or key members of Congress are out of office by the time it is settled? House Oversight Chairman Elijah E. Cummings (D-Md.) has already had to postpone his subpoena to Mazars accounting firm while he waits for the courts.

5. Does Trump or his business have any money laundering ties? House Intelligence Chairman Adam B. Schiff (D-Calif.) wants to know this. The House Financial Services Committee is also looking into potentially sketchy financial deals by the Trump Organization and his son-in-law’s former company. They’ve subpoenaed bank and lending records from Deutsche Bank and Capitol One, but Trump sued to try to stop this.

How this could escalate: Trump lost that lawsuit. But could his lawyers appeal and drag this fight out to run out the clock?

6. Getting Trump’s tax records: Treasury Secretary Steven Mnuchin decided he will not let the IRS hand over Trump’s tax records to the House Ways and Means Committee, which is looking at how the IRS audits presidents. Trump has refused to publicize his tax returns even though other presidents have. In May, New York lawmakers passed a bill that would allow Congress to get the president’s state tax returns.

Treasury Secretary Steven Mnuchin. (Erik S. Lesser/EPA-EFE) (Erik S Lesser/EPA-EFE/REX/Shutterstock)

How this could escalate: The chairman of the House Ways and Means Committee subpoenaed Mnuchin to hand over the tax returns. Congress could also sue him to get them. They may have gotten an assist from the IRS itself, which had written a draft memo saying that the Trump administration did have to turn over taxes to Congress; that the law is clear. This case could go to the Supreme Court and take years to resolve.

On Trump’s other actions as president

7. Understanding Trump’s security clearance process: The same House oversight committee looking into Trump’s finances is investigating whether the White House gave top-secret security clearances to people who may have had drug, criminal or financial problems. This investigation has the potential to catch Trump in a lie about whether he overrode security clearance experts to give his son-in-law Jared Kushner access to the nation’s biggest secrets.

How this could escalate: Congress is working with a whistleblower and wants to talk to her former boss at the White House, Carl Kline. It subpoenaed Kline, but the White House told him to ignore the subpoena. So Kline never showed up for a hearing. Now the House Oversight Committee is considering voting to hold Kline in contempt, which could eventually lead to daily fines or the threat of jail time until he agrees to talk to lawmakers.

8. How did the Trump administration decide to add a citizenship question to the 2020 Census? As advocates challenge the legality of adding the question to the 2020 Census in the Supreme Court, the House Oversight Committee has subpoenaed the Justice and Commerce departments to learn more about it. Democrats and immigration activists worry that adding this question to the census could discourage immigrant communities from answering and, thus, hurt their representation in Congress.

How this could escalate: On Wednesday, the committee will vote on whether to hold the heads of the Justice and Commerce departments, Barr and Wilbur Ross, in contempt for not complying with the subpoenas. But Barr said if that happens, he’ll just tell Trump to exert executive privilege over the information. It’s not clear what Congress could do from there.