HANNIBAL, Mo. – Chris Koster came to Hannibal for the annual Democrat Days gathering seven years ago this weekend as a first-time Democrat.

It was the then-Repbulican state senator’s first large Democratic gathering after announcing his switch from the Republican Party, and he said he was nervous. So nervous, he brought his mom.

The wariness that he may have faced during his first trip to Democrat Days was nowhere to be found this year, as attendees rushed to grab photos with the state’s now second-term attorney general and encouraging him as he readies to be the party’s standard-bearer in 2016. Here in Hannibal and elsewhere on the campaign trail, Koster does not shy from talking about his party switch. And when he brings it up, he gets cheers.

Speaking here on Saturday as the party’s presumptive nominee for governor in 2016, Koster said the same issues that brought him to Hannibal after leaving the Republican Party in 2007 are the issues that the state is facing, yet again, in 2014.

“I quit my party over a disagreement over public health,” he told Democrats gathered for an annual brunch.

Koster touted his support of the 2010 federal health care law, noting new access to contraceptive services for women and a provision barring insurance companies from denying coverage based on preexisting conditions. Koster questioned why Republicans were against the policy, parts of which were first pitched by conservative groups in the 1990’s as an alternative to then-First Lady Hilary Clinton’s health care proposal.

“The Affordable Care Act was a Republican idea, for goodness sake,” he said. “It’s an honest to god Republican idea, they’re just pissed we stole it.”

Koster said perhaps his biggest frustration with his former party’s health care positioning now is its opposition to Medicaid expansion.

“This expansion proposal is the best darn economic development proposal this state has seen in the last 25 years,” he said. “For no other reason than because Barack Obama passed it, this legislature is willing to deny the health and economic benefits of expansion simply to spite a president.”

Koster noted support from the Missouri Chamber of Commerce and former U.S. Sen. Kit Bond, a Republican who was a vocal opponent of the 2010 health care law, which was passed during his final year in the Senate. Koster said the potential economic benefits of Medicaid expansion are undeniable.

“The bill has been passed. Sen. Bond is walking the halls trying to convince Democrats and Republicans to accept $2 billion,” he said in an interview. “If you had $2 billion dollars sitting on your front door, wouldn’t you take it?”

One reason Republicans offer is broad public opposition in Missouri and elsewhere to the federal health care law. When different provisions of the law have been on the ballot, Missourians have overwhelmingly opposed them. Still, Koster said he believes Medicaid expansion is different.

“The Affordable Care Act is unpopular, but the $2 billion federal offer and the expansion of economic opportunity that is being offered to us doesn’t strike me as unpopular,” he said. “Increasingly when I talk with members of the General Assembly, including Republicans, they are looking for a way out of this.”

Koster’s vocal support of the federal health care law stands in contrast to his only announced Republican opponent, former House Speaker Catherine Hanaway, who has voiced opposition to the law in full, including the Medicaid expansion provision.

“I am against any further expansion of Obamacare. Therefore, I am against Gov. Nixon’s proposed expansion of Medicaid,” she said earlier this month. “I lived through the expansions of Medicaid that Gov. Carnahan put on the books and the strife required to shrink back those expansions when the state could no longer afford them.”

Hanaway said she, like Republicans in the General Assembly, believes it would be “ill-advised for Missouri” to accept the federal funds when they will be rolled back in 2020, requiring the state to take on a 10 percent share of the burden.

Koster was the keynote speaker at the morning brunch in Hannibal. Secretary of State Jason Kander was scheduled to speak Saturday evening to the annual dinner.