Politicians, of all political stripes, should be legally obligated to disclose how they make their money and where that money comes from. Citizens have a right to know who or what is influencing a candidate for office. Money can often be a corrupting factor, but even if it's not, it's still the right of the public to know so we can make as an informed decision as possible when voting.
Yes, politicians should have to disclose their financial details because they are running for political office and their elect-ability is predicated on being transparent in terms of their professional and person conduct. This includes being fiscally responsible and being able to manage one's own life. In summation, a person who runs for political office is supposed to represent the values of the people he/she represents. In order to do so, those people have to be sure that their candidate best is able to live up to such expectations.
In today's world of special interests, political candidates should definitely have to disclose financial details when running for office. Otherwise, there is no guarantee they aren't doing things to strictly benefit themselves. Unfortunately, politicians cannot be trusted and this information needs to be disclosed. Politicians already get away with way too much.
We need to stop demanding that some candidates be fully open while others get to pick and choose what they disclose. Average Americans have to disclose financial information such as credit ratings in order to get some jobs, there is no reason that politicians shouldn't face the same scrutiny as everyone else.