E. J. Dionne Jr. acknowledges the valuable role of third parties but still wonders if they should be allowed into the presidential debates [op-ed, June 30]. This isn't rocket science. Why is it that we can put a man on the moon but can't come up with a way to elect our president that allows voters to vote for their favorite candidate, allows multiple candidates to run and present their issues and ensures that the winner has majority support? The real fault lies with our presidential election method (also used to elect our congressional and state legislatures), which allows a candidate to win whether he or she has majority support or not. It defies the principle of "majority rule." If we used a runoff election or an "instant runoff," which elects a majority winner in one round, the "spoiler" problem would go away.  Why not criticize our election method instead of the candidates?