I just looked on Wikipedia. I didn't notice that he did something before he started staffing with DC Senators.
Regardless, There is only two ways to get that wealthy while in congress: Graft or insider trading. Probably a little of both.
There’s a third way: marriage.
Does anyone really think John Kerry married the Widow Heinz for love?
Elaine Chou may have had humble beginnings, but as a former Labor Secretary she’s certainly well positioned enough to have legitimately (speaking fees, corporate board positions, etc) built that kind of a nest egg within a few years of leaving office.