Jeb Bush is getting increasingly feisty with surging rival Marco Rubio

Former Florida Gov. Jeb Bush (R) is now drawing his sharpest contrast to date with Sen. Marco Rubio (R-Florida), his surging rival in the presidential race.

In television interviews on Wednesday and Thursday, Bush pointedly noted that Rubio served as a state lawmaker when he was governor.

"Because I'm a proven leader," Bush told CNN's Dana Bash when asked why voters should pick him instead of Rubio.

"I disrupted the old order in Tallahassee. I relied on people like Marco Rubio and many others to follow my leadership. And we moved the needle: led the nation in job growth, reduced the role of government, reformed the things that were broken, took on some very powerful interests, and we won."

Bush then compared Rubio to President Barack Obama, who was also a relatively young freshman senator before launching a potentially history-making bid the White House.

"Look we've had a president who came in and said the same kind of thing - 'new and improved,' 'hope and change' - and he didn't have the leadership skills to fix things," Bush continued. "What we need is someone with proven leadership."

Bush, who is often described as Rubio's political mentor, has up until recently been relatively muted in his criticism for the senator. But with Rubio rising in the polls and Bush becoming increasingly feisty on the campaign trail - especially when it comes to Republican front-runner Donald Trump - that appears to be changing.

Indeed, Bush doubled down on the Obama comparison in a Thursday interview on MSNBC's "Morning Joe."

"Marco was a member of the [state] House of Representatives when I was governor, and he followed my lead. And I'm proud of that," Bush said.

Asked if Rubio has the leadership skills required to fix Washington, Bush replied: "It's not known. Barack Obama didn't end up having them."

Bush was not the first person to compare Obama to Rubio, who has repeatedly called the comparison misguided. According to PolitiFact, Rubio said in an April interview that his résumé in Florida politics was much deeper than Obama's in Illinois.

"I certainly feel I'm running for office with much more experience and qualifications than Barack Obama had when he ran. When Barack Obama ran for president, he was basically a state legislator from Illinois that had served in the Senate for two years," Rubio reportedly told the Des Moines Register's editorial board.

"I, on the other hand, have been a legislative leader from the third-largest state in the country who has served in the Senate four and a half years, and have invested a significant amount of time in national security issues."