Whether it was the correct decision or not, it is unsettling to see the president of the United States fire the FBI director while the bureau investigates the president's campaign advisers and former top aides for connections to Russia.

For the sake of the rule of law, in order to preserve and restore public confidence in our law enforcement and government, and in the interest of basic propriety, President Trump owes it to the country to replace the fired James Comey with a director who is fiercely independent and who has a proven career of objectivity.

Republican senators must make it crystal clear that they will accept no less.

Trump must resist the urge to nominate a friend, a proven ally, or an old hand from his business days or his campaign. This is not the job for a sidekick or a right-hand man. The FBI director is not an arm of the chief executive nor is it even like a Cabinet head, who can be independent in a sense while still be part of the same team. The FBI director isn't part of the president's team.

Thanks to the nuclear option triggered by former Sen. Harry Reid, Democrats lack the ability to block Trump's pick. It takes only 51 votes in the Senate (or 50 plus the vice president) to confirm the next FBI director. That puts a great responsibility on the shoulders of Republican senators.

To uphold their duty to the Constitution, GOP senators should make it clear — it would take only a delegation of three — that they will reject any nominee who reeks of cronyism, who looks like a stooge, or who seems to lack the qualifications and independence to conduct the business of the FBI as it needs to be conducted.

Such a message, sent immediately, should deter Trump (if he is so tempted) from picking a friend or loyalist for the office.

There are plenty of places to look for a qualified FBI director. The ranks of career FBI officials would be one place to start.

If Trump wants to shake up the agency with an outsider, he could do a lot worse than picking a judge. Find an old Reagan appointee on the federal courts who has amassed decades of fealty to the law regardless of party. Find a state judge who has enjoyed bipartisan support in his or her confirmations and whose only loyalty is to the rule of law.

The FBI director's job is not an easy one. Trump, however, can easily find many qualified and proven public servants who could carry out the job with skill and independence. It's up to Republican senators to guarantee Trump doesn't seek to fill this role with anything less.

The issue isn't merely the Russia investigation. People in power tend to abuse power, and that's especially true near the pinnacle of power. Our republic only works when we know that even the president of the United States is subject to the law.

Democrats and liberals are already likening Trump's firing of Comey to Richard Nixon's Saturday Night Massacre in which he axed those lawyers who refused to put politics ahead of duty. This seems a bit ridiculous, given that they have been calling for Comey's head for months. But if Trump picks a crony to replace Comey, he will prove them right.