This logical fallacy is easy to get caught up in. This fallacy is an attack on the character of your opponent rather than the merits of the argument. While I will never say whether I voted Democrat, Independent, or write in candidate in the last presidential election, it is a well known fact that I did not vote for Donald Trump. The reasons that I don't think he is the right candidate are almost all related to his character. That said, even a blind squirrel gets a nut sometimes. He may come up with a plan that has value and merit. He hasn't, in my opinion, as of yet, but that's not the point of this.
If I am debating with someone, for instance, Donald Trump, and I am opposed to his argument, or his stance, I cannot challenge his character as a good reason to be against this argument. For example, if he says that homosexuals should be married in civil ceremonies only, and I want to oppose that, I can't say that's a stupid plan because you're a womanizer who cheats on his wife, therefore you have no authority. His marital sexual escapades have no bearing on your knowledge of the law, constitutionality, nor feasibility of your plan. Let's face it, Bill Clinton was somewhat similar in his alleged escapades, and we let him stay president. Donald Trump has suffered the same allegations, it doesn't matter in terms of the argument at hand.
It's easy to attack a conservative or a liberal for holding beliefs you do not like. It is also easy to shut out a solution simply because you do not like the author of the solution. That is 99% of the issues in the US today. We don't like the other side, so we don't want to meet half way. IF you want your argument to be valid, refrain from attacking the other side's character. Attack, instead, the other side's argument.