Former U.S. Attorney General Jeff Sessions and President Donald Trump spent a portion of the Memorial Day weekend attacking each other on Twitter as Trump reiterated his support for former Auburn College football coach Tommy Tuberville in Alabama's Republican Senate runoff:

Donald J. Trump

@realDonaldTrump

Jeff, you had your chance & you blew it. Recused yourself ON DAY ONE (you never told me of a problem), and ran for the hills.  You had no courage, & ruined many lives.  The dirty cops, & others, got caught by better & stronger people than you. Hopefully this slime will pay a big....price.  You should drop out of the race & pray that super liberal @DougJones, a weak & pathetic puppet for Crazy Nancy Pelosi & Cryin' Chuck Schumer, gets beaten badly.  He voted for impeachment based on "ZERO".  Disgraced Alabama. Coach @TTuberville will be a GREAT Senator!

Trump had previously stated that had he known that Sessions would recuse himself from what he calls the "Russian hoax" investigation called for by then–FBI director James Comey, he would have never hired him.  Because of the recusal, it was left up to Deputy Attorney General Rod Rosenstein to appoint former FBI director Robert Mueller as special counsel to oversee an investigation into allegations of Russian interference in the 2016 presidential election and any related matters with the Trump campaign.

Sessions responded by saying: "I will never apologize for following the law and serving faithfully and with honor.  Neither of us knew about the phony investigation into our campaign until after I was sworn in.  As you will recall, I recommended firing @Comey from the very beginning."  He added: "You and I fight for the same agenda.  Alabama will not take orders from Washington on who to send to the Senate."

If we recall, during Sessions's confirmation hearing for attorney general before the Senate Committee, he testified under oath he "didn't have communications with the Russians."  He had to later retract his statement after it was disclosed that he had had two meetings with the Russian ambassador, Sergey Kislyak, during the campaign. 

"In retrospect, I should have slowed down and said I did meet with one Russian official a couple of times," Sessions said after the disclosure — he recused himself from the investigation just a day after, saying he did not feel he should investigate a campaign he had a role in.  By stepping down, the investigation was handed over to former special counsel Robert Mueller.  Sessions resigned as attorney general in 2018 and was replaced by William Barr.

I must admit that initially I had defended Sessions's decision to recuse himself, after the quoted Department of Justice (DoJ) Title 45.2, b, until I read the fine print of the DoJ's regulation on Disqualification arising from personal or political relationship, which states:

(a) Unless authorized under paragraph (b) of this section, no employee shall participate in a criminal investigation or prosecution [highlighted for emphasis] if he has a personal or political relationship with:

If one reads Comey's explanation to the Senate Select Committee on Intelligence, the Mueller probe was neither a criminal investigation nor a prosecution:

It is important to understand that FBI counter-intelligence investigations are different than the more-commonly known criminal investigative work. The Bureau's goal in a counter-intelligence investigation is to understand the technical and human methods that hostile foreign powers are using to influence the United States or to steal our secrets. The FBI uses that understanding to disrupt those efforts.

Sessions's claim that he had to recuse himself makes his decision pretentious at best.  As detailed by Andrew C. McCarthy, senior fellow at the National Review Institute:

[C]ounterintelligence investigations should not trigger disqualification or recusal of an attorney general unless and until the investigation turns up incriminating evidence that could form the basis for a criminal investigation — and a possible prosecution. If that happens, the attorney general (or any other Justice Department official in a recusal situation) not only should but must apply the disqualification rule, and should recuse himself if the criminal investigation involves the kind of conflict of interest — based on a personal or political relationship — set forth in the regulation.

After a 22-month investigation, Mueller's team did not find sufficient evidence to establish that a criminal conspiracy took place between the Trump campaign and the Russian government.  While Mueller declined to make a determination about whether Trump may have obstructed justice, he did lay out 10 instances of possible obstruction that Democrats viewed as a road map to continue investigating and possibly seek his impeachment.

Attorney General Barr, after receiving the Mueller findings, determined that there was no collusion with Russia on the part of the Trump campaign and that there was no evidence the president had obstructed justice.  Barr has recently been accused of "re-examining" the Russian probe during his six meetings with U.S. attorney John Durham six times last year.

I am not taking a position on the senatorial race between Sessions and Tuberville, especially since the latter previously criticized Trump "for illegal aliens' obtaining 'cell phones, healthcare, everything they want' after they arrive in the U.S. in audio that was previously not reported on."  The point to be made is that while Sessions was quite clear and strong against illegal immigration during his two-year tenure as attorney general, he does appear to have "jumped ship" when President Trump needed him the most.