>Given that the current president is right wing, wouldn't the left have a vested interest in talking about self-dealing in the state?

If there wasn't a permanent bureaucracy of sorts, then yes, but in this case there is in fact a permanent bureaucracy, what some call the deep state, which is a constant regardless of which party is in power. And this political bloc overwhelmingly supports the Democrats and is threatened by potential cuts from Republicans.

Covering self-dealing within the state would give the Republicans' efforts to cut some of these programs and departments moral legitimacy in the public eye, so left-wing news sources would not do that.