In the case of someone new to government and running for office, I see this as a dangerous precedent. The obstacles to running for office are already daunting, so that many a good public servant has been dissuaded from running. I can see it if done voluntarily, if by popular demand there is significant reason to question finances.
But in the case of people who have been in Congress for many years, even decades, and live high in opulent mansions, some kind of public review of their financial condition might be in order. It's not hard to imagine the resistance that idea would have, even by those who most loudly call for it from others.