Gov. Jay Nixon announced his full support for expanding the state’s Medicaid program, a key provision of the Affordable Care Act that he contends will bolster the state’s economic fortunes and help an estimated 300,000 poor Missourians get access to health care.

But the Democratic governor’s advocacy could face a steep challenge in the Republican-led Missouri General Assembly, unless GOP legislators make an about face from their decision in 2005 to cut eligibility for the health-care program for the poor.