Sen. Ben Nelson (D-Neb.) is pushing for a change to the chamber's healthcare bill that would allow states to opt in or out of the "reformed health care system" Democrats are proposing.

His amendment seems to be a response to growing concerns among local lawmakers that the Senate legislation's Medicaid changes could further complicate Nebraska's growing budget problems.

Nelson first mentioned the proposal in a letter to Nebraska Gov. Dave Heineman earlier this week, who strongly opposes the healthcare bill's proposed expansion of Medicaid.

Wrote Nelson in the letter:

"In your letter you note that the current Senate bill is not in Nebraska's best interest. I agree. That is why I continue to work to change it. Please be advised that I have proposed that the Senate bill be modified to include an "opt-in" mechanism to allow states to avoid the issues you have raised. Under my proposal, if Nebraska prefers not to opt in to a reformed health care system, it would have that right."

It is unclear whether Democrats will offer Nelson's proposal as part of their Manager's Amendment, which should be public by Saturday morning. Efforts to reach Nelson's office were unsuccessful.

But previous experience dictates the caucus is skeptical of healthcare reforms that permit states the ability to decide whether to implement them -- a fact that seemed most evident when the Senate's bill contained an "opt out" public option clause.

Nevertheless, Heineman is among a handful of governors who have railed against the upper chamber's healthcare bill, fearing an expansion of Medicaid could further dent their already holey budgets.

“The State of Nebraska cannot afford an unfunded mandate and uncontrolled spending of this magnitude," Heineman wrote to Nelson. "Additionally, Nebraskans are very concerned about the bill’s increase in payroll taxes. Rural hospitals are very concerned about their ability to survive. Seniors are very concerned about the cuts in Medicare."

“The bottom line is the current Senate bill is not in Nebraska’s best interest," the governor added. "Therefore, I strongly urge you to oppose the current Senate health care legislation."

However, Nelson may ultimately oppose that vote, regardless of Heineman's beckoning: The Nebraska senator still opposes the bill because its abortion language "isn't sufficient," he previously said.