In 1958, Mildred and Richard Loving were arrested in their own home, in the middle of the night, for the crime of miscegenation. When the Supreme Court declared miscegenation laws illegal in 1967, 16 states still had such laws on the books. A new poll released this week by the Pew Research Center shows just how far we’ve come in the five decades since the Lovings’ arrest. 15 percent of new marriages in 2010 crossed racial or ethnic lines, double the rate from 1980. And a great majority of Americans say they would readily accept an interracial marriage in their family. Renee Romano is professor of history at Oberlin College and author of “Race Mixing: Black-White Marriage in Postwar America.”