“Alabamans don’t like to be told what to do,” Ms. Gitcho said, adding, “They have shown that repeatedly. Washington told them to vote for Luther Strange over Roy Moore, they disobeyed. Washington told them to vote for Roy Moore over Doug Jones, they disobeyed. They are a hardheaded and independent lot.” She said that Mr. Sessions “is indeed one of the strongest supporters of President Trump and his agenda” and “no one can change that.”

Mr. Trump has been focused on the Alabama Senate race, consulting in recent weeks about it with his political advisers Bill Stepien, Justin Clark and the White House political director, Brian Jack, according to people familiar with the discussions.

Mr. Trump has a unique level of anger at his former attorney general. In 2017, Mr. Sessions surprised Mr. Trump by recusing himself from the investigations into Russian interference in the 2016 presidential race.

That recusal led to a series of actions by Mr. Trump that resulted in the appointment of the special counsel, Robert S. Mueller III. Mr. Trump, according to a half-dozen current and former advisers, viewed Mr. Sessions’ recusal as an act of disloyalty and a political form of original sin, from which he never recovered.

Mr. Trump fired Mr. Sessions in late 2018.

In the context of his campaign mail pieces, Mr. Sessions and his team may be acting in ways that are more political than delusional. Highlighting a connection to Mr. Trump could help Mr. Sessions with voters in Alabama who haven’t been following the president’s yearslong denigration of the former attorney general and senator, who at one point was the first statewide elected official to support Mr. Trump’s presidential bid.

Despite the vitriol that Mr. Trump has aimed at him on Twitter and at campaign rallies, Mr. Sessions has never publicly criticized the president, the way many former administration officials have.

And trying to create the impression of an endorsement, or support, of a politician popular with one’s own party, when one hasn’t actually earned it, is a tactic that candidates in both parties use often. Most recently, Senator Bernie Sanders of Vermont, who is running for president, ran a television ad with a voice-over from President Barack Obama that seemed to imply that Mr. Obama was throwing his support to Mr. Sanders. Mr. Obama has not endorsed any candidate in the presidential race.