IT MUST have seemed like a good idea at the time. Why not get rid of an irksomely independent FBI director, who was making trouble for Donald Trump’s White House, by exploiting his mishandling of Hillary Clinton’s e-mails? After all, Mrs Clinton believes that James Comey cost her the presidency with a letter informing Congress in October that he was reopening the investigation into her use of a private e-mail server. Surely Democrats would be glad to see the back of him.

Mr Trump has the power to sack Mr Comey. But nobody will be fooled by the quasi-prosecutorial memo drawn up by the deputy attorney-general, Rod Rosenstein, at the president’s request. If the trouble were Mr Comey’s handling of Mrs Clinton’s e-mails, he could have been sacked four months ago. Indeed, Mr Trump had praised Mr Comey’s October letter, saying it had taken “a lot of guts”.

That leaves two interpretations (see article). Either Mr Comey was dismissed in an effort to undermine an investigation into collusion between members of Mr Trump’s campaign and Russians trying to subvert the election. Or Mr Trump got rid of him in a fit of pique. Maybe Mr Comey was just too big for his boots, too unwilling to take the president’s paranoid notions seriously—say, by failing to credit his idea that Barack Obama had ordered a wiretap of Trump Tower. Either way, the sacking of Mr Comey reflects terribly on Mr Trump.

There is as yet no proof that aides close to Mr Trump were conspiring with Russian intelligence agents. But officials and the president’s toadies in Congress, such as Devin Nunes, chairman of the House Intelligence Committee, have behaved as if there was something to hide. Mr Nunes had to withdraw from his committee’s investigation after appearing desperate to do the bidding of the White House. The attorney-general, Jeff Sessions, who gave misleading testimony about his contacts with Russia’s ambassador, has similarly recused himself. Mike Flynn had to quit as national security adviser after lying about his dealings with the Russians. Mr Comey’s defenestration just as he was asking Mr Rosenstein for more resources to look into Russia only fuels suspicions of a cover-up.

If Mr Trump is lashing out at an uppity underling, that too is a bad sign. It suggests the president does not respect the vital principle of an independent, non-political FBI—which, for all his faults, Mr Comey represented. Taken with the contempt Mr Trump has shown for judges who challenge his executive orders, America’s system of checks and balances is under stress.

Some, including Chuck Schumer, the Senate’s top Democrat, have called for an independent counsel to continue the investigation. But there is a problem. It would be the now-compromised Mr Rosenstein who would be responsible for making the appointment and for oversight of what followed.

Country first

Congress must now uphold constitutional norms. Any successor to Mr Comey nominated by the president must face the most rigorous examination of their impartiality. But that will not be enough. What is needed is either an independent commission, along the lines of the one set up to inquire into the events leading up to September 11th 2001, or a bipartisan select committee to investigate the Russia allegations. Neither would have prosecutorial powers, but they could have substantial investigatory resources and be able to subpoena witnesses. There is no reason why prosecutions could not follow once they had reported. Principled Senate Republicans, such as Richard Burr, Ben Sasse and John McCain, are troubled by what the removal of Mr Comey portends. It is high time for them and others to put their country before their party.