When I got married in California in 1959 there were almost 20 states where marriage was limited to two people of different sexes and the same race. Eight years later the Supreme Court unanimously declared state bans on interracial marriage unconstitutional.

Recently, Ted Olson and I brought a lawsuit asking the courts to now declare unconstitutional California's Proposition 8 limitation of marriage to people of the opposite sex. We acted together because of our mutual commitment to the importance of this cause, and to emphasize...