CNN
WASHINGTON (CNN) - President Obama's speech to Congress Wednesday on health care reform will probably be one of the high-noon moments of his presidency.
[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/POLITICS/09/08/congress.trigger/art.obamaflag.gi.jpg caption="President Obama has faced pushback from members of his party on a public health care option."]
Surrounded by liberals demanding a government-run public option and centrist Democrats - along with Republicans - who want to dump the option, Obama just might have his finger on something that can get him through this health care showdown: the "trigger" option.
The idea would give insurance companies a defined period to make changes in order to help cover more people and drive down long-term costs. If those changes failed to occur within the defined period, a trigger would provide for a public option to force change on the insurance companies.
Watch: Pressure on public option 
A public option is a government-funded, government-run health care option, similar to Medicare. Under the plan, people would pay premiums 10 to 20 percent less than private insurance.