1. Eliminate the income tax, go back to the traditional tariff revenue system and yes- cut spending to live within the revenue generated thereby. Worked for the first 150 years of the Republic, and would do more to end porkbelly politics and stimulate the domestic economy than either raising taxes or, conversely, "targeted tax cuts" ever could.
2. No more popular election of Senators. That would do more for "campaign finance reform" than any single thing I can think of.
But of course neither of these two reforms will ever happen. :(