NOTA would be far more effective than campaign-finance reform in reducing the overwhelming advantages of incumbency. In many races, second-rate incumbents win by beating third-rate challengers. With NOTA, a sitting officeholder could lose an election and give another candidate a chance even in a hopelessly gerrymandered, one-party district. And if NOTA came at all close to winning, even the most entrenched incumbents might be forced to rethink their positions and inject some needed humility into their approach.
An election where even an unopposed incumbent isn't safe? Now that's something I could get behind. The ability to walk into the voting booth and explicitly offer a vote of "no confidence" would completely change the entire American political landscape.