Let me say something here about corruption. It isn't necessarily illegal.
To me, corruption is when money is what is running things. And there's plenty of money flowing into the campaign funds of congressmen and senators. It comes from corporations, who are mostly Republican oriented because they are perceived to be business friendly. It comes from the NRA. It comes from everywhere. And you know the saying, when money talks, people listen.
There's also under the table money, which is clearly illegal.
All of this happens at all levels of government, although more money goes to the places where it makes the most difference. That's just good business practice, I suppose. But it a congressman has a "safe" seat, I don't imagine he would get so much money, unless he happens to have a lot of power in congress, but most of the power in congress is with those with "safe" seats.
You might get the idea that voters don't get much of a hearing. After all, you only get to vote for one congressman and one senator, although everyone gets to vote for president. In other words, at most, only two people represent me in congress and I might not have even voted for them.