This has been a big week in the presidency of Donald J. Trump, wouldn’t you agree?

The former acting attorney general of the United States, Sally Yates, testified Monday that she warned the Trump campaign about Michael Flynn’s association with Russian government officials.

Then on Tuesday, the president decided to fire FBI Director James Comey, whose agency is in the midst of investigating questions surrounding the former national security adviser.

The firing has shocked and stunned much of Washington, D.C., and — I venture to guess — much of the rest of the nation, too.

What in the world does one make of this?

Trump’s letter to Comey discusses something about his conduct regarding the Hillary Clinton e-mail matter that erupted 11 days before the presidential election. So … he waits until today — May 8 — to pull the trigger on Comey?

I don’t know about you, but something smells badly here. It stinks. It reeks.

There’s going to be some gnashing of teeth for a few days. Then what?

Here’s what I think ought to happen. I believe it is monumentally imperative that Congress — House and Senate, Democrats and Republicans — declare the need for an independent prosecutor to continue this Trump-Russia probe. There can be no hint, not a whiff, of bias in this investigation.

Comey told a congressional committee that his office was examining questions about whether the Trump campaign colluded with Russian government officials who — according to intelligence agencies’ assessment — sought to interfere with the 2016 election. Has any of it been proven? No, although the ranking member of the House Intelligence Committee, Democrat Adam Schiff, has said there appears to be something “more than circumstantial evidence” to pin the collusion charge on the Trump campaign.

Still, the investigation must continue. Can a Trump appointee as head of the FBI be trusted fully to do what he or she must do to root out the truth? Call me a skeptic — even a cynic, if you prefer — but I have grave doubts that the president is going to nominate a truly independent FBI director.

We’re hearing words like “Nixonian” to describe what Trump has just done. President Nixon fired the independent prosecutor who was zeroing in on the White House during the Watergate scandal. As we know, it didn’t work out well for the president, who quit his office just as the House of Representatives was preparing articles of impeachment against him.

This latest matter has taken a dramatic turn for sure.

It’s timing of this dismissal that has awakened a lot of Americans.

Mr. President, you need to explain yourself. Now!