Because the 'incumbents in Congress/Senate only have to be elected by a very small loyal constituency in their own states.The majority of the people are FED UP with the government and the media.
It that's the case, why do the incumbents in congress keep getting re-elected? Something like 94%.
You know, with everybody being pissed off at them.
Congressional/Senates state races are controlled by whichever 'old boys club' has the most money to put up TV ads. Most potential voters are literally so fucking stupid and out of touch with what's happening three blocks from where they live the incumbent just has to go on TV and tell the viewers what a great job he/she is doing and the vast majority will think "If that's the case I don't need to vote".
Then the extremely intense phone calls to those who did vote last time start: "You HAVE TO VOTE! If our boy looses you're brother-in-law's Government gravel hauling contract is in jeopardy!