Democrats who run the Minnesota House narrowly failed Monday to override Republican Gov. Tim Pawlenty’s veto of an expiring state health plan for the poor, falling four votes short.

House Republicans united to sustain the veto, blocking Democrats from getting the 90 votes required to override a veto.

The 86-47 vote happened as Pawlenty’s administration moved forward with a plan to switch the patients into another health plan designed for a different group. The Department of Human Services began changing software over the weekend and said counties would start sending notices Tuesday informing General Assistance Medical Care patients about the April 1 transfer.

Democrats argue the switch would move many poor patients from a free program to one that will ultimately charge them a monthly premium, and will leave hospitals with more uncompensated costs.

The dispute over the General Assistance Medical Care program may shift to the courts.

Democratic House Speaker Margaret Anderson Kelliher suggested that someone might sue to stop the switch, although she didn’t name any groups and none immediately came forward. She said Democrats won’t go along with transferring the patients into the MinnesotaCare health program for the working poor.

“It will push working Minnesotans who pay their premiums every single month out of coverage,” said Kelliher, one of 13 Democrats who are running for governor.

Pawlenty’s plan would transfer those now covered by General Assistance Medical Care to MinnesotaCare, which requires monthly premiums and offers limited hospital coverage. General Assistance Medical Care covers more than 30,000 adults with yearly incomes of less than $8,000, including many with chronic health problems, drug and alcohol addictions and mental illness.

Pawlenty thanks GOP House members for upholding his veto and invited Democrats to his office on Tuesday.

“I’m hopeful they’ll come back to the table now that this pathway didn’t work for them and try to find a pathway to a solution that works for Minnesota,” Pawlenty said.

He said he would keep pressing for payment changes that reward doctors whose patients do well. He said a potential lawsuit would be “unfortunate” and “a strange strategy” that could block coverage for the affected patients.

Democrats said Monday’s vote had been their best option to preserve adequate coverage for the General Assistance Medical Care patients. Rep. Erin Murphy of St. Paul, the bill’s sponsor, said it would be more difficult to negotiate a solution as Pawlenty’s transfer moves forward.

“Today we are fighting for the vulnerable. Today we are fighting for what we believe,” Murphy said on the House floor. “Today is policy before politics.”

Murphy’s bill won bipartisan support last month, passing on a 125-9 vote before Pawlenty vetoed it. Republicans who voted ’yes’ came under pressure from local hospitals, faith groups and others to break with the governor and enact the legislation.

Some of that pressure showed during a spirited floor debate.

Rep. Leon Lillie, a Democrat from North St. Paul, read from the Bible, a verse from Matthew that said, “I was sick and you looked after me.”

“There’s no shame for me or anybody that votes ’yes’ on this,” Lillie said. “There’s no shame for anybody that votes for the needy in our society.”

Some Republicans, including Rep. Tony Cornish of Good Thunder, bristled at that.

“I have a heart, too, and just because I vote against the override doesn’t mean I’m any less of a Christian than you,” Cornish said.

Republicans accused Democrats of trying to hurt Pawlenty with the vote, calling instead for continued negotiations over the future of those covered by the program. Some wanted to wait for an updated budget forecast coming Tuesday.