After spending the early months of his campaign on the defensive, Maryland gubernatorial candidate Douglas F. Gansler has pounced on an issue on which he believes his leading rival is vulnerable: the botched rollout of the state’s online health-insurance exchange.

On Thursday, the Gansler campaign issued its latest attack on Lt. Gov. Anthony G. Brown, accusing the fellow Democrat of dodging the news media and ducking responsibility for a task assigned to him by his boss, Gov. Martin O’Malley (D).

“The people of Maryland, and all of us who supported the Affordable Care Act, deserve a full accounting,” Gansler’s running mate, Del. Jolene Ivey (D-Prince George’s), said in a news release that included links to a television news report critical of Brown’s role and a Washington Post editorial that called Maryland’s online exchange “an embarrassment.”

Brown responded Thursday by saying he bears some responsibility for the technical glitches and other problems that have led to lower enrollment in Maryland than in other states that chose to run their own exchanges under the federal health-care law. But he said the real issue now is what to d o about it.

“Everyone that was involved in [setting] up the exchange is responsible, and that includes me,” Brown told reporters. “My responsibility and focus is on fixing the exchange and addressing the challenges that we face.”

It’s unclear how much blame Brown might ultimately shoulder, particularly in a Democratic primary six months off in a state where recent polls have shown that President Obama and his signature initiative both enjoy more support than most anywhere else.

But the repeated attacks on the health-care exchange’s rollout have knocked Brown off stride for the first time in the campaign, and they show how scrappy and spirited Gansler remains despite a series of serious setbacks that marred his debut as a candidate.

Brown’s running mate, Howard County Executive Ken Ulman (D), took a shot at Gansler later on Thursday, saying the state’s Democratic attorney general has sounded “like a Republican criticizing affordable health care rather than being a part of the solution.”

In June’s primary, Gansler and Brown will face Del. Heather R. Mizeur (D-Montgomery), who has largely stayed out of the fray.

Shortly after Gansler’s candidacy was announced in September, the race became dominated by headlines about police accounts that Gansler allegedly ordered state troopers who drive him to unnecessarily speed and run red lights, and about a teenage beach party attended by Gansler where there was apparently underage drinking.

In an interview, Ivey said the Gansler ticket is trying to focus the race on issues. “This is one of Anthony Brown’s big issues,” she said of health care. “He’s done a bad job.”

Brown does not directly oversee the day-to-day operations of Maryland’s insurance exchange, which is run by a newly created agency. But he was appointed by O’Malley to co-chair a commission with the state’s health secretary that is supposed to be guiding health-care changes in Maryland.

During his campaign, Brown has frequently cited increased access to health care as one of his accomplishments, and he and O’Malley have spoken enthusiastically about implementing Obama’s changes in Maryland.

“He bragged about it, he pounded his chest — and then he went to sleep,” Ivey said of Brown. “If this had gone well, he would have been touring the state and taking credit.”

Maryland’s problems have been similar to those that have plagued the federal government’s Web site, Although Obama officials declared last weekend that most of those have been addressed, Maryland is still working out its bugs. Problems include screens freezing and error messages that don’t indicate the action to take.

At a news conference last week, O’Malley said most problems should be taken care of by mid-month and accepted responsibility for what he said was “a risky launch” in October.

Maryland officials have been able to point to some signs of progress. During the week ending Nov. 23, more Marylanders chose to sign up for private plans through the exchange than any previous week.

Still, the 3,024 people who had done so leave Maryland a long way from a target of signing up 150,000 people by the end of March. An updated figure is expected to be released Friday.

“You’ll see that we continue to enroll more Marylanders, and I think you’ll see that the rate of enrollment is increasing as well,” Brown said.

Brown told reporters Thursday that he plans to talk at greater length about the exchange next week.

“Both the governor and I are certainly focused on fixing the exchange and getting it right,” he said. “I’m going to make myself available, and I’m also going to provide regular updates.”

Ulman said that Gansler could have directed more workers in his office’s consumer division to help implement health-care reform.

Ivey said such criticism is “silly” and dismissed Ulman’s contention that Gansler sounds like a Republican for questioning Brown’s leadership. “I don’t understand how we can sound like Republicans when Doug Gansler and I are enthusiastic about Obamacare and enthusiastic about Obama,” she said.