Congress must represent and serve its people. Too long in office, they lose touch with their constituents' needs and grow more accepting of the corruption and graft in DC. They grow dependent on campaign donations from corporations and lobbyists. There may even be a chance that this can undo some of the damage done by gerrymandering. Candidates would actually have to appeal and be accountable to their constituents rather than depend on voters defaulting to their incumbent at election time.