To unseat an incumbent in today’s system, a US House challenger has to raise an enormous amount of money

WASHINGTON — Former White House speechwriter and congressional candidate Josh Gottheimer had more money in the bank than anyone else looking to oust a U.S. House incumbent, Federal Election Commission records show. Gottheimer had $2.5 million in the bank as of June 30, more than any other House challenger of either party. He is opposing Rep.…