In this day and age, voting is relatively easy. It's pretty obvious which candidate of the major parties is the better choice.
This wasn't always the case.
Let's pretend it's the year 1800. The Constitution is relatively new, we are a third world country.
We have two candidates. Thomas Jefferson and John Adams. Both were strong advocates for declaring independence. Both are critics of Slavery. Jefferson favors a more states-rights oriented approach to the constitution, while Adams prefers a stronger English-style federal government. But they both generally agree with James Madison and the Federalist Papers.
Who would you support? I tend to lean Jefferson, because of his "Of the People" rhetoric. Jefferson was a believer in democracy by the Common Man. But I think both were major contributors to our Democracy.