As Mitt Romney’s tenure at the helm of Bain Capital continues to be a focus on the campaign trail, the incoming chairman of the National Governors Association argued over the weekend that the presumptive GOP nominee’s private equity background should not be out-of-bounds.

Delaware Gov. Jack Markell (D). (Alex Brandon/AP)

Markell, who formally took the reins of the NGA on Sunday, has a private-sector background that bears some similarities to Romney’s. He holds an MBA from the University of Chicago and launched his business career as the 13th employee at telecommunications giant Nextel. He later worked at Comcast, McKinsey and Co. and First Chicago Corp. before winning election as state treasurer in 1998.

Markell pointed to some of the similarities between his own and Romney’s background and contended that “there’s a huge issue here of what is it that you learn from your experience in the private sector.”

In particular, he pointed to the moment in a GOP presidential primary debate last August when all eight candidates raised their hands when asked whether they would reject a “grand bargain” on the debt that included a 10-to-1 ratio of spending cuts to tax increases.

“One of the things I see as a big distinction is Romney and essentially all of the people who were running for president on the Republican side were running on, ‘No taxes, no litigation, no regulation,’ ” he said. “Now, it’s not that those three things are unimportant. But the fact is ... there are plenty of places around the world where there are no taxes, no litigation, no regulation, and they tend to be places without a very strong middle class.”

Republicans have argued that Obama’s proposal to extend the Bush-era tax cuts for those with incomes of $250,000 or less would represent a tax hike for small businesses who have the greatest impact on job creation.

“President Obama’s announcement this morning will mean a tax increase for millions of families, job creators and small businesses,” Romney spokeswoman Andrea Saul said in a statement this month. “Governor Romney knows that job-killing tax increases will hurt our troubled economy even further, and he has a plan to lower the rates and broaden the base without increasing the deficit to encourage investment and job creation.”

Romney’s campaign did not immediately respond to a request for comment Monday on Markell’s remarks.