This document summarizes universal suffrage and voting demographics in the United States. It outlines that all U.S. citizens 18 and older have the right to vote in all political elections. It then analyzes voting patterns by gender, age, education level, and race/ethnicity in the 2012 election, showing differences in support between Democratic and Republican candidates among various groups. Finally, it lists several constitutional amendments that have expanded voting rights over time to include more groups.