The president had wanted to spend the last few weeks, when lawmakers were back in their home states for August recess, reconciling the two bills, but instead August was defined by confusion, fear, anger and opposition to health care reform, as illustrated in many raucous town hall meetings.
Analysts said the president's speech needed to acknowledge the new landscape and not rehash what Americans have heard from him before.
"This is make or break time for President Obama on health care, because the public has turned so sour and he has a divided Congress. He needs to first rally the Congress, but more importantly, he needs to turn the tide of public opinion," said political analyst David Gergen. "This speech has upsides but it's also a very potentially tricky, very treacherous speech for him."
Gergen said the president's plan needs to be simple and specific, one that would convince lawmakers and citizens that it won't break the bank and get government involved in people's medical decisions.
"What he has been doing in the last few weeks has not worked, so this is clearly time to hit the reset button and reframe the argument, and that means he has to not only find a simple plan, but he has to come up with fresh ways for the public to understand it and to support it," Gergen said. "This is the 11th hour in the health care fight, and this is time for him to take charge, to rally the Congress and to rally the country. That's what's important in this speech."
One of the key points of contention that Obama will likely have to address is the idea of a government-run insurance plan that would compete with private companies. Republicans said a public option plan would drive private companies out of business and lower the quality of care Americans get. Some citizens who have shown up at town hall meetings have expressed concern that such an option would entail a government takeover of their health care coverage.
The president has enough support in the House for a public option plan, but he may not get the same camaraderie from the Senate.
If Obama doesn't push the public option, "that is going to bring a howl from his Democratic left" and "the unions that would be all over him," Gergen said. At the same time, "it may work with the public."
"We'll have to wait and see," Gergen added.
Beyond State of the Union speeches, addresses to joint sessions of Congress -- the definition of the presidential megaphone -- are rare. Presidents George W. Bush and Bill Clinton gave only two each in their eight years in office.
In fact, 16 years ago this month, Clinton gave an address about health care reform -- an anniversary the White House likely wants to forget, considering that the Clinton administration's health care push was unsuccessful.
ABC News' Huma Khan contributed to this report.