One of those associates said that Senator Mack, 58, had simply decided that "it is time to move on."

But Senator Mack, who said he hopes to move forward with the bill late next week, acknowledged that it faces a rocky road.

"And we want it done right," Senator Mack said, "with less government and more freedom."

"What we should be saying is that the anxiety is coming about because of the high tax burden on the economy," Senator Mack said.

A cancer survivor, Senator Mack has also been a strong advocate for cancer research, early detection and treatment.

"Every question raised in the federal court process has been a series of technical legal questions," Senator Mack said.

Senator Mack shares the drug industry's opposition to price controls, saying such restrictions could dry up money needed for research into new drug therapies.

He also noted that the money would not become available until Senator Mack left office.

The only problem is that Senator Mack will not be on the ballot.

But Senator Mack emphasized that "it's fair to say" the idea gained "momentum over the weekend."