There is not a single "small government" politician, though Ron Paul is probably close. It's all bullshit. They are all power-hungry statists, the very definition of big-government. It just comes down to WHICH parts of the government they want to be big/powerful and what areas of your life they want to fuck with.
Unless you want to drastically cut military spending ( among other things), and get completely the fuck out of people's private lives and property, the small government is just bullshit campaign rhetoric. Like George Bush campaigning on a humble foreign policy against nation-building and a somewhat libertarian ( well, except for a lot of the "compassionate" bullshit) domestic agenda. All bullshit.