Do you really think the authors of the Constitution intended that non-local entities could contribute all the money they wanted to elect your congressional and state representatives? Also, when the Constitution was written, there were no unions, no corporations, no political parties and no PACs.
Constitutional amendment or whatever, something needs to be done. Our political system is corrupted by money. For any political party to gain and retain power, it requires huge amounts of campaign money and the way that works now is destroying our country.