Democrats have another reason to be optimistic about Tuesday’s presidential election after the release of a new Gallup poll. Gallup, which is considered one of the more reputable polling organizations operating today, doesn’t do election horse-race polls of candidates. However, it does measure public opinion in other important ways that could predict how an election may turn out. On Thursday, Gallup released a series of polls exploring voter enthusiasm among supporters of both major parties and compared it to voter enthusiasm in past election cycles. The organization also gauged at how effecti…