Longtime late Sen. John McCain (R) aide Mark Salter criticized the National Republican Senatorial Committee on Twitter Saturday for trying to undermine Rep. Krysten Sinema’s (D) lead in the Arizona Senate election.

“Stop doing this, NRSC,” he wrote.

“McSally is losing fair and square, and she’s underperforming in more than Maricopa. The race is almost certainly lost and nothing will change that. All this does is poison our politics more. Despicable.”