Double all federal election and campaign contribution limits in "exchange" for 35% of the total amount of the contributions be collected by the federal treasury for sole purpose of buying down national debt. The 35% fee would be eliminated once the national debt is eliminated.
Those donating to individual campaigns should not only support a candidate/party but the overall solvency of our national budget. Increasing the donation power of persons or groups increases their influence on the political landscape but also positively supports the nation as a whole.
The 35% can be viewed as a "cover-charge" for donating to your favorite candidate/party. Thus, those that do not want to support the country as a whole as well as their party, need not to donate at all.