Mueller, the former director of the FBI, leads the Justice Department’s probe into the Trump campaign’s attempted collusion with the Russian government. The inquiry appears to be gaining steam; in late July, the FBI raided the home of former Trump campaign chairman Paul Manafort . Americans deserve to know what happened last year, and any wrongdoers should be brought to justice.

Congress is considering new legislation to protect special counsel Robert Mueller, but what it needs to do sooner or later is set a red line for President Trump: If the president fires Mueller or sabotages his investigation, he’ll be impeached.


Trump, though, has mused publicly about firing Mueller. He also launched an attack on his own attorney general, Jeff Sessions, that was widely interpreted in Washington as laying the groundwork to fire Sessions and shut down the investigation. The president has also sought to tell Mueller what he can and can’t investigate, hinting that scrutiny of Trump’s personal finances would be unacceptable.

Unfortunately, it’s very possible that he means it. Trump already fired former FBI director James Comey, which he acknowledged was because of the Russia investigation. Firing Comey may itself qualify as obstruction of justice; firing Mueller would qualify beyond any doubt.

Members of Congress, alarmed by Trump’s threats against Mueller, have introduced two bipartisan bills that would complicate any White House effort to remove him. One proposal, from Democratic Senator Cory Booker and Republican Senator Lindsey Graham, would require judicial approve to fire a special counsel. Meanwhile, Democratic Senator Chris Coons and Republican Senator Thom Tillis crafted a bill that would specify that only a Senate-confirmed attorney general could fire a special counsel, who would be able to challenge his removal in court.

Both bills would limit the president’s power over the Justice Department, and potentially set up a constitutional clash over separation of powers. Although the Supreme Court upheld the legality of the now-defunct independent counsel law in the 1980s, there’s no guarantee that either bill would prove constitutional.


And as critics have pointed out, neither would prevent a president or pliant attorney general from sabotaging the investigation in other ways, such as defunding Mueller’s office. The president could also hand out pardons to figures in the case, potentially including himself, short-circuiting the investigation even without firing the prosecutor.

The fact that the bills have attracted such surprising levels of support reflects the reluctance of Congress to use the remedy that they already have: impeachment and removal from office. Congress — and especially congressional Republicans — don’t want that. From their standpoint, protecting Mueller from getting fired is also a way to protect themselves from having to make tough choices in the event of a constitutional crisis.

That reluctance is understandable. Impeachment should be the last resort.

Still, the Booker-Graham and Coons-Tillis bills — or whatever combination emerges — ultimately only put up speed bumps. If the president is truly determined to derail Mueller’s investigation, he’ll probably find a way to do it — with defunding, pardons, firings, or all of the above.

By all means, Congress should go ahead and pass a bill to protect Mueller. But if they want that law to achieve its goal of ensuring a full investigation into Russian meddling, lawmakers will need to send the message that they’re also prepared to use the power that they already have if the president stands in the way of justice.