What Roosevelt and Churchill decided was the route to victory in WWII was through Europe. They had to win the war they had to win in Europe first. Doing something about television, to continue the analogy, would follow. Television is the Pacific Theater of campaign reform. Fear of outsiders is just one of the things driving the cost of campaigning.
Television advertising is the other.
I would hope that containing outside spending might make it possible to get votes from the majority caucuses for spending limits. There is no doubt that controlling the costs of television campaigning would almost assure those votes. The hope, of course, is that any reduction in the power of money will result in a compensating rise in the power of people, which will, in turn, bring back the old politics in a new form, but with voters not money playing the main roles. The difficulty of doing this reminds me of the story of the man who found a bottle with a genie inside. The freed genie offered the obligatory wish.