SPRINGFIELD -- As President Obama pushes health care reform, Springfield doctors are pondering the impact of a government insurance option. It's the most ambitious and controversial part of his pitch for reform: a public option that would compete with private insurance companies to provide healthcare to millions of uninsured people.

Donn Sorensen, executive vice president of St. John's Health System, thinks a government option could hurt instead of help access to coverage.

"To the extend that government gets involved in a big way, there are some unintended consequences," said Sorensen.

The aim of the president's plan is to cover more people -- many with pre-existing conditions -- who can't afford private insurance because of the astronomical cost.  

"There has to be a public option," health care advocate Lisa Fowler Koeppe of Springfield said in a phone interview.  "Covering some of these people with pre-existing conditions is just not profitable for the private insurers."

In a virtual town hall meeting Wednesday, the president focused on how more choices would provide people better benefits.

"This is going to be a marketplace to allow you to one-stop shop for healthcare plans and compare benefits and priorities in simple easy to understand language," said Obama.

But placing the government in the pool as one of those competitors makes Sorensen nervous. The fear is, since the government's option would be cheaper, many would ditch their private care for Uncle Sam.  That would, in turn, squeeze insurance companies out of the market and leave doctors with much of the tab.

"If you go to this public option -- that already pays providers at a lower rate and is scheduled to go lower in this bill -- there won't be any doctors there that can afford to take you in," Sorensen argued.

Congressman Roy Blunt, who has been charged with leading the Republican Party's alternative to Obama's plan, has also drawn the line in the sand on a government-backed option.

"We believe his plan ensures, guarantees, you won't be able to keep what you have because a government competitor is never a fair competitor," Blunt said in Springfield last week.

Sorensen and Blunt instead favor market-based incentives that would drive hospitals and specialty groups towards a more integrated care model.  They think boosting efficiencies, eliminating duplicate tests and focusing on prevention will help drive down costs.

Those are some areas where the president agrees with his rivals but the core of the disagreement remains whether to allow the government in the game at all.   Sorensen said that the government option could become cheap enough for patients to afford but too cheap for doctors to actually provide.

"Where every person may have insurance, the access to care wouldn't be available," he said.

For more of the political news of the day, hit up the KY3 Political Notebook.

For up-to-minute news updates, follow Dave Catanese on TWITTER.