Some studies show this could reduce uninsured residents in Southeast Missouri by as much as 31 percent, the largest of any section of the state.
Area Republicans, however, are concerned the long-term fiscal impact of the proposal could create deficits in other areas, such as education.
Nixon answered critics during a news conference at Three Rivers College by saying the federal Patient Protection and Affordable Care Act calls for the expansion of state services, and the law has been upheld by the Supreme Court and funded by Congress.
"This is not the time to argue the merits of this act," Nixon said, adding the choice now is not whether to follow the law, but how to implement it.
Nixon's proposal would lower the eligibility level to 138 percent of the poverty level for a family of four, which would equal an annual income of $31,809.
By expanding Medicaid by 2014, he said, the federal government will pay 100 percent of the costs for the first three years.
More than $8 billion dollars in federal money would come to Missouri by 2020, according to the Missouri Foundation for Health (MFH), by which time the cost of the expansion to the state will not exceed 10 percent.
If Missouri passes on this opportunity, Nixon said, it will still get the bill, but not the benefits.
"This is a question of whether or not to put Missouri tax dollars in Missouri hands, or in the hands of other states. The clear choice is to put past differences behind us," Nixon said, saying earlier this is the right thing to do to cure a system that serves uninsured Missourians in an expensive and scattershot way, which passes the costs on to all Missourians.
The MFH study, completed with the University of Missouri, estimates the state's costs from 2017 to 2020 at almost $333 million.
District 153 Rep. Steve Cookson, R-Poplar Bluff, said his greatest concern about the expansion was the long-term affects on other state services.
"With the expansion of Medicaid, I fear that will take up an enormous part of our state budget and it will severely limit and alter the amount of money we have for other state services, such as public education," said Cookson, adding he had not heard the governor's statements Thursday and could not address those specifically. "I do understand the federal government is supposed to fund it at 100 percent, however, I worry about our national debt and what that's doing to drive our national debt further up."
Cookson said he is also skeptical about some of the rhetoric concerning funding coming out of the federal government.
Nixon has said the additional funding for health care will create an additional 24,000 jobs in 2014 alone.
The MFH study supports this prediction, going on to state more than 1,700 of those jobs would be in Southeast Missouri and reduce unemployment in this region by more than 15 percent.
Poplar Bluff, MO