My actual opinion has more nuance, but for the sake of a short statement, I believe that spending on political campaigns should be very limited.
Campaign contributions should be capped for individuals, corporations, and organizations.
Spending on political advertising should be restricted by date, perhaps six weeks before an election.
I don't know how to limit Political Action Committee spending without restricting organizations such as The Red Cross, Planned Parenthood, etc, but something needs to change there.
In general, less money in politics, more transparency about where money comes from.