Don't miss the interesting trick that's not mentioned here. Sure, sure, one can skirt campaign contribution limits, which admittedly, can be an advantage in a heavy challenge in a district. But any candidate for federal office can also be paid, by the campaign, a salary equivalent to the federal office they are seeking.
She gets to personally pocket more than a hundred thousand dollars for /just/ being a candidate.
Yup, nothing quite so corrupt as a government official. The difference between a Republican and a Democrat is that the Republicans are usually embarrassed by it, while the Democrats try to out do each other.