(CNN) - Sen. Rob Portman's son Will tweeted congratulations to his father for his op-ed piece in Friday's Columbus Dispatch in which he explains his reversal on same-sex marriage.
"Especially proud of my dad today," the Yale junior tweeted in response to the Republican senator telling of his change of heart after Will announced that he was gay.
Portman explained his decision in the op-ed, in a handful of interviews with Ohio news outlets and in an exclusive interview with CNN Chief Congressional Correspondent Dana Bash.
In the op-ed piece, Portman writes, "As a congressman, and more recently as a senator, I opposed marriage for same-sex couples. Then something happened that led me to think through my position in a much deeper way."
In the interview with CNN, Portman tells Bash, "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."
Will Portman, 21, lists international development, prisons, Latin America, and whitewater kayaking among his interests on his Twitter page.
As news of his father's decision dominated headlines Friday morning, the number of Will Portman's followers on Twitter jumped from a few hundred to more than a thousand within a couple of hours. The tweet itself was retweeted more than 850 times as of 10:30 a.m. ET.