I forget who told this one to me. I am terrible at discussing politics, and this joke never fails to get me safely away from a discussion, or in some cases escape from people who approach me at random (e.g., at a gas station, or a queue for soup) and with whom I almost certainly share no political values, and it also never fails to get agreement from all parties:
“Politicians should be guaranteed two terms: Once in office, once in jail.”
And, with more wisdom than wit, Robert Heinlein:
If you are part of a society that votes, then do so. There may be no candidates and no measures you want to vote for but there are certain to be ones you want to vote against. In case of doubt, vote against. By this rule you will rarely go wrong.
If this is too blind for your taste, consult some well-meaning fool (there is always one around) and ask his advice. Then vote the other way. This enables you to be a good citizen (if such is your wish) without spending the enormous amount of time on it that truly intelligent exercise of franchise requires.