Page Pate , a CNN legal analyst, is a criminal defense and constitutional lawyer based in Atlanta. He is an adjunct professor of law at the University of Georgia, a founding member of the Georgia Innocence Project , a former board member of the Federal Defender Program in Atlanta, and the former chairman of the criminal law section of the Atlanta Bar Association. Follow him on Twitter @pagepate . The opinions expressed in this commentary are his.

(CNN) If I had a dollar for every time I heard the words "special prosecutor" over the past week, I would have enough money to qualify for a cabinet position in the Trump Administration.

Various Democratic senators have been calling for a special prosecutor whenever they can get close enough to a microphone. Last week, a number of state attorneys general wrote a joint letter to Deputy Attorney General Rod Rosentein urging him to appoint an independent special prosecutor. The New York Times Editorial Board joined the chorus a few days ago.

The idea of appointing a special prosecutor to take over the Russia investigation is not new. In March, a public opinion poll suggested that two-thirds of Americans supported the appointment of a special prosecutor. That was before Comey was fired, and before the competing excuses for firing him that came from the White House and President Trump himself.

A few months ago, I predicted that Trump might fire Comey. (I'm not happy I was right, and the writing on the wall was clear enough for anyone who cared to look.) I thought back then that the only way to move forward with a credible investigation into Russia's involvement with the last election would be to appoint a special counsel.

What was a good idea then is a necessity now. It's not just because Trump pulled the trigger on firing Comey. Although it's unusual, it's not illegal for a President to fire an FBI Director. A President can hire and fire executive branch officials as he sees fit.

And that's the problem. Trump can remove anyone and everyone holding a top position at the Justice Department who may be involved in this investigation. Clearly, he's not been shy about sacking Justice Department officials. Just ask Sally Yates and Preet Bahrara , or the other 46 US Attorneys who were told to vacate their offices before sundown earlier this year.

Let's imagine for a minute that the people in charge decided that appointing a special prosecutor was the right thing to do. This is how it would work . The attorney general (or the deputy attorney general in a case like this one, where the attorney general recuses himself) has the discretion to appoint a "special counsel" when: (1) a criminal investigation is warranted; (2) there is a potential conflict of interest if the Justice Department conducted the investigation, or there are "extraordinary circumstances" present; and (3) it would be in the public interest to appoint a special counsel.

The decision by the deputy attorney general to appoint (or not appoint) a special counsel is not be reviewable. Although political and public pressure can certainly influence the decision, it's entirely up to Rosenstein to do it or not.

I know that, according to sources cited by CNN, Rosenstein doesn't see the need for a special counsel at this point. He's wrong. It doesn't really matter if there is nothing to the allegations of Russia's meddling in the election or collusion with the Trump team. At this point, there is so much distrust and skepticism about the process itself that there needs to be an independent prosecutor looking into these allegations just to assure the country that the President and his associates did not commit a crime.

Rosenstein shouldn't get any friction from his boss. Attorney General Jeff Sessions has publicly recused himself from any investigation dealing with Russian meddling, and Sessions had no problem with the idea of a special prosecutor when the potential target was Hillary Clinton.

I recognize that there are legitimate arguments against the appointment of a special counsel. The process can be expensive, lack clear direction, last for a year or more, and is not guaranteed to reach any meaningful conclusions. But the benefits of appointing a special counsel in this case greatly outweigh the potential downsides.

Although no one has asked me (and no one probably will), I know just the person for the job: Larry Thompson, a former deputy attorney general and former US attorney in Republican administrations.

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He has extensive private sector experience, and is currently trusted by a federal court to oversee Volkswagen's compliance with criminal sanctions related to its emissions scandal. He is a loyal Republican and a supporter of Sessions , so the GOP couldn't credibly claim he's politically biased. More importantly, he's well-respected, extremely competent, and experienced in complex criminal investigations.

Whether it's Larry Thompson or someone else, a special prosecutor should be appointed to take over this investigation. If Rosenstein is the man everyone says he is , I believe he will appoint a qualified, independent prosecutor to take over this mess of an investigation.

Mr. Rosenstein, the ball is in your court. Don't let America down.