Sen. Rob Portman supports same-sex marriage in exclusive CNN interview

Sen. Rob Portman, a conservative Republican from Ohio, announced his support for same-sex marriage in an exclusive interview on CNN. Portman, who has voted for the Defense of Marriage Act in the past, says he had a change of heart on the issue after learning that his 21-year-old son is gay.

"I've come to the conclusion that for me, personally, I think this is something that we should allow people to do, to get married, and to have the joy and stability of marriage that I've had for over 26 years. That I want all of my children to have, including our son, who is gay," Portman told CNN's Chief Congressional Correspondent Dana Bash.

Portman, who was on Mitt Romney's short list for vice presidential candidates, says he told Romney about his son when he was vetted to be the Republican candidate's running mate for the 2012 election. While Paul Ryan was ultimately chosen over the Ohio senator, Portman says his son's sexuality did not play a role in the decision.

Dana Bash joins "Starting Point" on Friday to discuss her exclusive interview with Portman and why he decided to open up about his reversal on same-sex marriage.