For a long time I've thought the basic problem of the political system is that rich people can spend $0.05 cents to save $1.00 in taxes; if political donations were more expensive, say it cost $20.00 to save $1.00 in taxes, rich people would just pay taxes.

Various routes:

(1) Much greater spoils to political candidates and their hangers on

(2) Handicap elections, subtract a vote for every $20 in donations

(3) $500 of political donations means a crew goes out to bust up your car window or something of that magnitude