The statement that the percentage of young people voting in presidential elections has risen sharply since 1972 is generally considered true. Historically, voter turnout among young people (typically defined as those aged 18-29) has fluctuated, but significant increases have been observed in certain elections, particularly in 2008 and subsequent elections.
It's important to note that while there have been notable increases in specific elections, overall patterns can vary, and turnout rates may still not be as high as those of older age groups. If you're looking for more specific statistics or trends, I can help summarize those as well!