Kansas GOP chair Mike Kuckelman sent letters to two Republican candidates — Susan Wagle and Dave Lindstrom — asking them to drop out of the race for U.S. Senate for the good of the party, the Kansas City Star reports.

Kuckelman told the candidates that continuing their campaigns will endanger the party’s ability to hold the seat in November after eight decades of dominance in Senate races.

Kuckelman’s warning is an indirect but unmistakable reference to former Kansas Secretary of State Kris Kobach (R), who lost to Laura Kelly (D) in the 2018 race for governor after a historically close Republican primary that featured numerous candidates. It’s also an indirect endorsement of Rep. Roger Marshall for the nomination.