When you go to a restaurant, a person hands you a list of all the foods from which you can choose, and even makes suggestions to guide your selection.
When you go to vote, someone hands you a list of all the candidates from which you can choose, but they're not supposed to make any recommendations, even if you ask them to.
If they did it might go something like this:
"Good evening and welcome to The Polling Place. I am Sergio, and I will be your poll worker this evening.
"We have a fine selection of candidates for any taste. For the main course you can choose between a classic bleeding-heart, liberal whiner with distinct socialist overtones, or a neofascist globalist bent on world domination by Corporate America. Or for something lighter, we have a couple of independents. One is largely soy-based and fully organic. The other comes with your choice of side arms. Neither one is expected to last through the whole evening."