In a midday press conference given by Barack Obama, the president stepped directly into health care reform's biggest sticking point--the private-public plan debate. Obama was asked whether a public plan will drive private insurance out of business.

"Why would it drive private insurance out of business?" Obama rhetorically asked. "If, if private, if private insurers say that the marketplace provides the best quality health care; if they tell us that they're offering a good deal, then why is it that the government, which they say can't run anything, suddenly is going to drive them out of business? That's not logical."

Liberals want health care reform to include a public option that would, ideally in their view, pressure insurance companies to provide better coverage and lower costs. Private insurers claim the plan will be too difficult to compete against.

Obama did offer a bone to critics. "There can be some legitimate concerns on the part of private insurers that if any public plan is simply being subsidized by taxpayers endlessly that over time they can't compete," he said.

But today's comments were Obama's most forceful public statement yet that liberals primary ambition for reform, that of a public option, was in his view “conceptually” correct. Obama did however stop short of answering whether the public plan was a "non-negotiable."