This is a better argument for the American public making in general poor choices and political parties giving them the kind of people they are apt to vote for rather than paying insufficient salaries.
There is no reason to believe that the factor dragging political quality into the gutter is insufficient salaries. The fact that the Republican party turned down higher caliber more capable candidates in favor of trump suggests that candidate quality is limited by voter choice not insufficient compensation.
These folks really are in fact deplorable and you need to appeal to at least a substantial minority of awful idiots to be elected president or if on team red most of them.
This is why every Republican president in half a century has been an embarrassment and every democratic relatively conservative because nothing else flies here and upping the ante won't help.