16- and 17-year-olds won't be able to vote in Tuesday's election. But if they really don't want to wait until 2016 to vote for a president, Argentinian citizenship is always an option.
Argentina just lowered its voting age to 16 ahead of 2013's presidential election. It follows Brazil, Ecuador, Nicaragua, and Cuba in making the move. (Though how much your vote counts at any age in Cuba is another question.) Austria became the first European country to lower the voting age to 16 in 2008.