Except that you ARE funding the parties you don't like if political contributions earn a tax deduction.  Remove all tax deductions for contributions, and then the parties ARE funded only by their contributors.  Personally, I'm in favour of eliminating all fundraisers in favour of per-vote subsidy, with no tax deduction available for political contribution.  For new parties, that's a hurdle, so perhaps there needs to be a fund-raising exemption for parties less than 4 years old, and eliminated once the election happens.