At what age must citizens be to be eligible to vote for President?

To be eligible to vote for President in the United States, citizens must be at least 18 years old. This requirement is established by the 26th Amendment to the U.S. Constitution, which was ratified in 1971. The amendment was enacted to extend voting rights to younger citizens, ensuring that those who are 18 and older have the opportunity to participate in the democratic process and vote for their leaders.

Voting age laws are important because they reflect the balance between allowing youth civic engagement and ensuring that voters have reached a level of maturity and responsibility deemed necessary for making important decisions affecting the country. Thus, the correct answer is that citizens must be 18 years or older to vote for President, which aligns with the Constitution's stipulations.