Mike Pence has got a lot of explaining to do

(CNN)A vice presidential debate is usually a high-wire act: two candidates battling in a high-stakes showdown, on one night only. In this election, it's a high-wire act juggling flaming torches above a lake filled with alligators. A presidential debate is, by contrast, fairly straightforward. But in a vice presidential debate, candidates need not only to defend their own record, and contrast it with their opponent's, but also to attack the other side's presidential candidate -- all while having their boss's back. See? Easy peasy. Wednesday's debate between Vice President Mike Pence and Sen. Kamala Harris will probably be more normal than the first presidential debate, where Donald...