Sen. Luther Strange of Alabama has a presidential endorsement and multimillion-dollar backing from establishment Republicans, but he can't shake suspicion about the circumstances of his appointment or speculation about whether he's under criminal investigation.
Strange is facing a stiff primary challenge from former judge Roy Moore, and President Trump will attempt to tip the balance campaigning with Strange on Friday, days ahead of the Tuesday vote.
The former state attorney general was appointed to the Senate in February by then-Alabama Gov. Robert Bentley as his office investigated Bentley during a complex scandal involving a mistress.
Opponents allege a corrupt trade between Strange and Bentley, who resigned as part of an April plea deal, and speculation abounds about whether authorities are working to determine what actually occurred.
"I heard Monday there is an active investigation," Republican state Rep. Ed Henry told the Washington Examiner. He declined to identify his source, but said he heard it was a state rather than federal probe.