Alaska Dept. of Health and Social Services Commissioner Valerie Davidson, left, speaks in Anchorage in July. During the news conference, Gov. Bill Walker, right, announced he intended to accept federal money to expand Medicaid coverage. (Mark Thiessen/AP)

Alaska’s governor won a legal victory Friday that, at least for now, will allow the state to begin next week to sign up more low-income residents for Medicaid — despite objections from state lawmakers.

The dispute in Alaska has emerged as the latest political and legal skirmish over the Affordable Care Act, lingering even after the Supreme Court two months ago upheld the constitutionality of a core aspect of the law that requires most Americans to have health insurance.

This most recent skirmish involves a decision that each state has faced in the past three years: whether to expand its Medicaid program, as originally intended by the 2010 law that has been reshaping the health-care system.

When Congress adopted the law, it envisioned that opening Medicaid to people with incomes up to 133 percent of the federal poverty level would be a major way to extend health coverage to people who were uninsured. But two years later, the Supreme Court ruled that each state was free to choose whether to broaden access to Medicaid.

In Alaska, Gov. Bill Walker, an independent, asked the Republican state legislature to approve a plan that he said would enable 41,000 more residents to join the program. Lawmakers resisted, and a month ago, Walker announced that he would bypass the legislature and accept federal money to expand the program, starting Sept. 1.

On Monday, Alaska’s legislative council sued the governor to try to block the expansion, arguing that only the legislature had the power to decide who was eligible for the program. Lawmakers asked a judge to issue a temporary order to block the start of sign-ups for Alaskans who qualify for the first time.

On Friday, Superior Court Judge Frank A. Pfiffner turned down that request. The judge said the legislators who objected had not proved so far that starting to expand the program would cause the state “irreparable harm” or that the governor had clearly overstepped his authority. ­Pfiffner said that he expected his decision to be appealed to Alaska’s Supreme Court.