John Warner, who is of no relation to Mark Warner, retired in 2009 after serving 30 years in the Senate. Mark Warner was elected to the Senate in 2008 and is currently serving his first term.
In an interview with The Associated Press, the elder and Warner praised Mark Warner for showing bipartisanship in an increasingly divided Congress.
"You see him crossing that aisle to try to form teams to solve problems," John Warner said. "That's so essential."
Mark Warner lost to John Warner in a 1996 campaign for the Senate. The AP pointed out that when Mark Warner became Virginia's governor in 2002, the two politicians set that race aside and went on to collaborate on issues such as defense funding and transportation infrastructure.
This isn't the first time John Warner has gone against his own party and tipped the odds in a Democrat's favor. In 1994, the stalwart Virginia lawmaker refused to endorse Republican Oliver North's bid for Senate. The move ended up bolstering Democratic Sen. Chuck Robb, who was reelected by a narrow margin.
"John Warner epitomizes what it means to be a senator," Mark Warner told the AP after the elder Warner attended his Senate swearing-in ceremony in 2009. "He's been a great friend of mine, and I was so proud to have him there."