The first poll, by Remington Research in November, had shown Flake with a 19-point net-negative approval rating among likely Republican voters, and that he trailed Republican state Treasurer Jeff DeWitt, 42 to 33 percent in a head-to-head.

The new poll was apparently conducted on behalf of former state Sen. Kelli Ward, who unsuccessfully challenged John McCain last year and is already in the race to challenge Flake. The numbers don’t come from a particularly reputable firm, and the result — Ward 30, Flake 23 percent — is a bit shady if only because there are so many undecideds.

On the other hand, as recently as September, Morning Consult’s ongoing series of surveys on senators’ approval ratings had Flake at a reasonable 41 percent approve/35 percent disapprove. But that was five months ago. Flake, a former House member who just barely won his first statewide election in 2012, has more than 17 months to recover, as Arizona’s primary is in late August. But he’s probably also the weakest Republican incumbent facing re-election in 2018.