The purpose of a debate

The purpose of a political debate is not to simply answer the question you are asked. I think you have to know that going into watching a debate. Sure, that's what the moderator wants and in many cases that's what the people would like to see.

But the purpose of a debate is for each candidate to effectively communicate their campaign message. That's it. If a question is asked and the candidate doesn't think his campaign message will be effectively communicated by answering "yes" or "no" to a "yes or no" question, he won't answer "yes" or "no". He will find a way to steer his answer in a direction so that it's consistent with his campaign message.

For example: the moderator asks, "Do you believe that if a pregnant woman dies, a death certificate should also be written for the unborn baby?" The purpose here is presumably to catch the candidate off-guard on a hot button issue, abortion. How would you answer? And isn't that a stupid way to ask the question, "What is your position on abortion?" The candidate may want to communicate his position on abortion, but finds this question rather irrelevant to the abortion debate. So, he steers the question in the direction that he prefers to go.

You may deem some questions worth being answered directly; the candidate, however, may not. So stop expecting them to answer every question directly. Stop hoping they won't attack one another. They're in the middle of a campaign. Everywhere they go their sole purpose is to communicate their campaign message. Understand that and realize that if you expect anything different, you will be disappointed.