I don't even blame those people. For example I am a car enthusiast but not a car engineer, so while I may love the Porsche brand for the emotional connections it has in my mind, a car engineer who really knows what he's talking about may very well know for a fact that the tech for part X is better in a Toyota. I don't know and I don't care.
People just get disappointed in politicians because they operate in an incentive system that rewards them for not keeping their promises, because votes are a 'sunk revenue' once in office. If laws were made in a private market, they'd be incentivized to be more consistent.
"Vote for higher welfare for lazy people? Get real?!? Vote down the poor food tax and WIN two year supply of McDonalds today![1]"
[1] Terms and conditions apply.
They wanted to believe. Even then Obama gave off considerable whiffs of being a relative political neophyte who felt entitled -- or even destined -- to power, and was given an easy path into the White House by an all-too-eager Democratic apparatus. Still, I was glad he won in 2008 because of his platform; he eventually reneged on so many of his campaign promises that I could not, in good conscience, vote for him in 2012.