Count Oklahoma Sen. James Lankford as a no on the Tax Cuts and Jobs Act, if the tax reform package causes the debt to rise too much.

“I am a no,” Lankford said when asked on NBC’s “Meet the Press” if he’d vote against the bill if it raised the nation’s debt too much.

“I want to make sure that we have reasonable assumptions in the process for growth estimates.”

It’s estimated the tax reform package will cost about $1.5 trillion in the short term, but Republican backers of the bill say the package will pay for itself over the next several years due to increased economic growth.

Lankford's possible opposition to the package may put Republicans on thin ice in the Senate again with a major legislative proposal. Republicans can afford two defections to pass the bill along party lines, but if three senators oppose the bill then it will die on the Senate floor like the majority party's attempts to repeal and reform the Affordable Care Act.

Lankford said the models used to estimate that growth have to be dead on for him to back the bill.

“I'm actually not comfortable with increasing the debt. This has been a behind the scenes conversation for a long time. It's one thing to be able to cut taxes. It's another thing to say how are we going to deal with our debt and deficit?” he said.

“My main focus has been whatever economic growth model we put in place has to be reasonable to do it. If we cut taxes right now, we're expecting a 0.4 percent growth in the economy to be able to offset that. That's a pretty conservative estimate of economic growth. Our economy for the last ten years has not grown above 3 percent a single year. We are stuck in a rut. We're going to have to bump the record player to get something going on the economy again and we want to be reasonable on our assumptions to do it.”