Terry McAuliffe said Wednesday that he knew nothing about a failed effort by his supporters to wrest an important business endorsement from Attorney General Ken Cuccinelli II, his Republican rival in the governor’s race.

McAuliffe also dismissed accounts that he had flubbed his interview for that endorsement by touting his ability to schmooze. And he backed off a campaign pledge that Republicans said amounted to a threat to shut down the government over Medicaid.

McAuliffe made those comments on a morning that began with a new Quinnipiac University poll showing the pair in a virtual tie. Talking with reporters after a Richmond forum on the economy and education, McAuliffe was on the defensive on a number of issues even as he projected an air of confidence.

“I’m not paying attention to polls,” he said. “I feel great about where we are.”

Cuccinelli, who also spoke at the forum, relished a seeming change in fortune, beginning with revelations over the weekend that McAuliffe supporters had tried to pressure the Northern Virginia Technology Council’s political arm to reverse its plan to endorse Cuccinelli.

“I think we have a lot of momentum, especially this week after the NVTC endorsement and how the other side handled it,” Cuccinelli said.

The NVTC’s TechPAC voted to endorse Cuccinelli last week but held off announcing that endorsement after McAuliffe allies protested. The Democrat’s camp devoted the weekend to furious but ultimately fruitless arm-twisting. Cuccinelli formally received the nod Monday.

Asked about the behind-the-scenes push to change the endorsement, McAuliffe said he was in the dark. “I don’t know anything about it,” he said, pivoting immediately to another subject.

The endorsement episode seemed especially damaging to McAuliffe because some members of TechPAC board’s said McAuliffe came off as ill-prepared and superficial in his interview with the group. As an Irish Catholic, he’d be good at schmoozing with people to support his agenda over drinks, McAuliffe told the board, two members told The Washington Post.

“These were partisan attacks. I mean, come on,” McAuliffe said when asked about the account. “I think what everybody knows is the amount of time that I have spent traveling to every nook and cranny in Virginia, talking about those issues that matter. I have put out a very substantive policy plan on all different issues. This is what I talk about from morning till night, seven days a week.”

McAuliffe also seemed to back off what had sounded like a solemn vow: not to sign a budget that does not include money to expand Medicaid under the Affordable Care Act. GOP leaders have said the campaign promise amounts to a threat to shut down the government given opposition to expanding the health-care program in the Republican-dominated House.

Asked whether he really meant that he would not sign a budget without the expansion, McAuliffe said: “I always say, ‘Please make sure you send a budget that has the Medicaid expansion.’ ” He has left off the “please” in at least three campaign appearances.

When pressed on his previous statements, McAuliffe suggested that he could talk reluctant Republicans into supporting expansion with a series of one-on-one meetings over meals.

“Here’s what we’re gonna do, after I get elected, the day after I get elected, I’m going to spend the ensuing couple months — I’m going to visit every single Republican House of Delegates member, every Republican state senator,” he said. “Breakfast, lunch, dinner, whatever it may be. I’m going to visit every single one of them.”

The candidates gave back-to-back addresses at the Virginia Summit on Economic Competitiveness and Higher Education, held at the Greater Richmond Convention Center.

In his speech, McAuliffe stressed the need for Virginia to diversify its economy through investments in education, particularly with the state’s defense-heavy economy likely to take a hit from federal budget cuts. He also said that Cuccinelli would make the state seem unwelcoming to scientists and gay university professors because of his conservative stance on gay rights and his “witch hunt” against a University of Virginia climate scientist.

“The commonwealth is a place [where] our professors, our scientists and innovators feel welcome,” McAuliffe said. “We cannot be putting walls up around Virginia. We have to attract the best and brightest.”

Cuccinelli touched on plans to promote school choice and shape energy policy. Happily playing the wonk, he delved into the nitty-gritty on some of those items and directed the audience to look up his detailed policy proposals on his campaign Web site.

“If you’re having trouble sleeping, you can try to read them all at once,” he said.

The speeches themselves fed into the narrative that emerged from the TechPAC flap: that McAuliffe is breezy while Cuccinelli grasps the details and gravity of the job. Both candidates had 45 minutes to address the group. Cuccinelli gave a 39- minute address heavy on wonky details. McAuliffe gave his standard 16-minute stump speech.