LITTLE ROCK, Ark. — Like their counterparts in other southern states, Arkansas Republicans denounced ‘‘Obamacare’’ during this year’s election campaign and called for its repeal. But now that they won control of the Legislature for the first time in 138 years, GOP lawmakers are considering something that would be anathema to conservatives elsewhere — expanding government health care in the state.

Instead of rejecting outright the idea of expanding the Medicaid program for the poor — an optional part of the new health insurance system — Arkansas lawmakers are exploring ways of adding up to 250,000 low-income residents to the rolls, which already include a fourth of the state’s population.