Fixing the wrong thing
Two things. First, the US presidency has become way too powerful and that's a much bigger problem just atm. Second, if you want to fix something about the US Congress, term limits are treating the symptom rather than the disease (and treating it badly, as they would simply guarantee that people in those jobs would lack experience). If you want to fix something, how about changing the way Representatives are elected, to eliminate first-past-the-post and single-member-district.