At the federal level, they're pretty much all bought and paid for other than one or two of them (Elisabeth Warren, Bernie Sanders). At the state level, though, even some of the Republicans aren't bought yet.
It won't be long until the state politicians are bought too and then it's all over. Americans need to take this seriously and ask their state representatives to get money out of politics.
There should be a general rule, in my opinion, if someone's ads are all over TV, then you don't vote for them. Those ads aren't free.
As the old saying goes, you get the government you deserve. If people don't pay attention, then their money will get siphoned off to be given to the rich people and corporations.