Sen. Tim Johnson endorses same-sex marriage

U.S. Senator Tim Johnson endorsed same-sex marriage today, the latest in a string of Democratic senators to change their positions on the issue.

"After lengthy consideration, my views have evolved sufficiently to support marriage equality legislation," Johnson said in a statement. "This position doesn’t require any religious denomination to alter any of its tenets; it simply forbids government from discrimination regarding who can marry whom."

Johnson had previous opposed same-sex marriage.

His endorsement followed that of two colleagues on Friday: Sen. Heidi Heitkamp, D-N.D., and Sen. Joe Donnelly, D-Ind.

Fifty-four U.S. senators now endorse same-sex marriage. Only three Democratic senators do not: Mary Landrieu of Louisiana, Mark Pryor of Arkansas and Joe Manchin of West Virginia.

Only two Republican senators take the same position: Rob Portman of Ohio and Mark Kirk of Illinois.