As a campaign manager, I'd much, much rather be running the guy with a message and no money versus the guy with money and no message. Why? Because the guy with a message will eventually find momentum, which will deliver all the money he needs when he needs it. - Patrick Ruffini
There's more at stake in the political process now than there has been in recent history. Whereas before the voters were happy to let the political establishment run on autopilot, now they want to assert more input. Therefore they're willing to take on more of the spadework themselves if their favored candidate has a message that's strong and clear.