Do you have to fill out your entire ballot? What to know about leaving fields blank while voting

As Americans go to the polls, some voters may — for whatever reason — decide they don't want to vote in every single race or on every initiative. 

Voting in some races, but not all, is called "undervoting." But in every single state, the ballot counts even if 

In other words, if you vote in only down-ballot races, or only in the presidential race, your ballot still counts, and your vote will be tabulated for whatever race or races in which you vote.