With the Massachusetts gubernatorial election only five days away, the candidates sparred last night in a passionate final publicly televised debate, taking the opportunity to discuss illegal immigration and gay marriage in between verbal spats.

Republican Lt. Gov. Kerry Healey tried to regain some ground in a race in which she is polling 25 points behind Democrat Deval Patrick, and apologized for mistakes she said her administration made in hiring Bechtel-Parsons Brinkerhoff to oversee Big Dig repairs. Many Boston officials consider Bechtel the cause of the I-90 tunnel collapse for improperly installing ceiling bolts.

“It was a terrible mistake, and [Transportation] Secretary Cogliano took responsibility,” she said. “They should not be allowed [back] into the tunnels in any capacity . . . they need to provide us with information so that we know how to fix these things that shouldn’t have gone wrong in the first place.”

Unsatisfied with the answer, Patrick blasted her for not receiving reparations from Bechtel.

“This is the most bearing determinate of a shoddy administration and leadership of this party,” he said.

In contrast to the candidates’ previous exchange, last night’s debate was free-flowing and allowed them to ask other candidates questions, and respond with a 20-second rebuttal. Both Healey and Independent Christy Mihos used this platform to their advantages, continually breaking out into back-and-forth argument, while moderator Cokie Roberts, a former ABC News anchor, struggled to maintain order.

“Your unfavorable numbers are at 59 percent,” Mihos said to Healey.

“You can’t win,” he added. “At this point why don’t you drop out and support me and let me have a chance.”

“You’ve got one idea, and Deval’s got none,” Healey responded, adding, “I’ve got 50 good ideas to move this Commonwealth forward.”

Mihos quickly responded, “I’ve got one good one: You should leave.”

Between squabbles, the candidates did addressed some prevalent campaign issues, including whether gay marriage should appear on the ballot and the state of Massachusetts’s education system.

Patrick said, “the sky hasn’t fallen,” since the state has legalized gay marriage.

“The courts affirmed that people come before the government as equals,” he said, adding that it would be upsetting to have a popular vote on an issue court officials have already ruled unconstitutional.

Healey responded that the issue should go to ballot because voters have the right to have their voices known.

When the candidates were asked what the basic role of the government should be, Healey seized the opportunity to speak about education.

“A key point in democracy is that we need to have public education,” Healey said.

“If you don’t have good education, you can’t have educated voters, and that’s important,” she continued. “Another fundamental aspect is to make sure all of our schools give all of our kids an equal shot at public education.”

Healey later went on to say that, “if schools aren’t safe, kids aren’t learning — they’re thinking about drive-by shootings or whether or not the kid next to them has a weapon.”

But on the topic of violence, Green-Rainbow Party candidate Grace Ross blasted Healey’s campaign tactics.

“[They] ran ads that traumatized women I know who have been raped,” she said.

The debate then turned to national security, sparking a heated discussion on border security and illegal immigration.

“The government must secure our borders,” Mihos said.

Deval said it is not hard to prevent illegal immigration — all the country has to do is “secure our borders.”

“If the administration in D.C. had done its job, we wouldn’t be having this conversation,” he said.

Healey used the chance to criticize Patrick on an issue she repeatedly brought up throughout her campaign: that Patrick wants to give illegal citizen’s driver’s licenses.

“You want to give them in-state tuition and drivers licenses, so they can disappear into society and get onto airplanes,” she said, at which point the crowd broke into boos and applause.

Deval dismissed her comments, saying he has taken the driver license issue off the table due to clarifications made by the federal government.

“I’ve made these points before and you didn’t listen,” he told Healey.

“I believe only citizens should have the right to vote, and in-state tuition should be for those who have played by the rules,” he added.