“Happy 100th birthday to the amazing Roberta McCain!” Lieberman tweeted.
He continued in another tweet, “It's no mystery where your son @SenJohnMcCain got his energy and personality from, but you are still much better looking than he is.”
McCain tweeted, “Happy birthday Mom!” earlier in the day, and pointed to his daughter’s column on Roberta McCain’s birthday.
McCain’s daughter, Meghan, who blogs at The Daily Beast, dedicated her column on Tuesday to her “Nana.”
Reporters on Twitter went on to note that McCain’s mom was a "fun" presence on the campaign trail during the senator’s bid for the White House in 2008.