But he said he was only interested in one campaign.
"To be honest," he told the Dallas-Fort Worth World Affairs Council, "I'm focused on the land commissioner race in 2014."
That's when son George P. Bush, a Fort Worth Republican, will launch his political career by running for a state office often seen as a springboard.
Introducing his father and celebrating his 37th birthday, the younger Bush joked that his dad enjoys his role as an "elder statesman" in the party's "gray area."
George P. Bush also joked that in Fort Worth, "We call it the Fort Worth-Dallas World Affairs Council -- That's a little touch of Amon Carter for you today," referring to the late Star-Telegram founder.
In a speech promoting his new book, Immigration Wars: Forging an American Solution, Bush told the audience head-on that growth through increased immigration would boost America's economy.
"High growth creates high optimism," he said, calling for the U.S. to "redefine the border" and saying he could support either a pathway to citizenship for illegal immigrants or just legal permanent residency.
"That's with one condition," he said: "Coming to the U.S. legally should be easier with less cost and risk than coming illegally."
Bush also spoke about education and said Florida's scores have improved since that state improved reading classes and ended social promotion.
He said he remains a "big believer in testing. Texas may have overdid it" -- he paused, grinned and corrected himself -- "overdone it."
Then he added: "Overdid it? That's the Midland version."