The entire point of an interview is to judge the person. Can they do the job effectively? I don't think that a tasteful or coverable tattoo is going to hinder you much. But if you have guns and dollar signs tattooed on your face, you're obviously an idiot.

It's too broad of a question, and the comments are addressing worst case scenario tattoos. That being said, having visible tattoos is certainly going to draw judgement, one way or the other. If someone doesn't like your tattoos they'll think less of you. If your tattoo is offensive, you're unhireable. Its similar to putting a bumper sticker on your car; you're allowed to express yourself, but if you do a lot of people are going to think you're an asshole. It's not a smart move unless you're going into an industry where maintaining a clean and professional image isn't that important.