Mitt Romney spent much of Thursday out of public view, huddling with advisers and speaking to donors at three high-dollar fundraisers, even as prominent conservatives griped about Romney’s spare schedule.

Romney held one public rally Thursday, appearing on stage for roughly 20 minutes.

But the former Massachusetts governor was invigorated on the stump, nearly shouting himself hoarse at times as he seized on President Obama’s comment at a Univision forum that he couldn’t change Washington from the inside.

“The president today threw in the white flag of surrender again. He said he can’t change Washington from the inside. He can only change it from outside,” Romney told to a rally of about 4,500 people. “Well, we’re going to give him that chance in November. He is going outside.

“I can change Washington, and I will change Washington,” he said. “We’ll get the job done from the inside. Republicans and Democrats will come together. He can’t do it. His slogan was ‘Yes, we can’; his slogan now is ‘No, I can’t.’ This is time for a new president.”

The Romney campaign began the day promising a more detailed discussion of issues, beefed-up public appearances and a greater television presence. The campaign released a television ad on Medicare featuring Sen. Marco Rubio (R-Fla.), who will be prominent in Romney’s attempts to attract Latino voters in Florida and across the country. Romney lags Obama among Latinos 68 percent to 26 percent, according to the latest tracking poll by Latino Decisions.

In the 30-second ad, Rubio says: “Mitt Romney and Paul Ryan get it. Medicare is going broke. That’s not politics. It’s math. Anyone who wants to leave Medicare like it is is for letting it go bankrupt. My mother’s 81 and depends on Medicare. . . . We can save Medicare without changing hers, but only if younger Americans accept that our Medicare will be different than our parents’ when we retire in 30 years. But after all they did for us, isn’t that the least we can do?”

The campaign has started to air the video at campaign events.

Next week, Ann Romney will sit for her first late-night interview, appearing Tuesday on “The Tonight Show With Jay Leno.”

Meanwhile, her husband is trying to reframe remarks caught on videotape at a fundraiser in Florida last May.

“This is a campaign about all of America, about the poor who want to break into the middle class, about the middle class who [we] want to give a break to,” Romney said. “They’re really struggling, the middle class, with those higher costs and lower take-home pay. I want to help all Americans, and my five points will do it,” a reference to his economic plan.

Gallup’s latest poll has the race tied at 47 percent to 47 percent.

Asked if he intended to campaign harder over the next weeks, Romney didn’t exactly answer.

“Ha ha. We’re in the stretch, aren’t we? Look at those clouds. It’s beautiful,” he said, pointing to the sky. “Look at those things.”

The news of his wife’s late-night appearance came on the heels of an announcement that the president and Michelle Obama will appear on “The View” on Tuesday.

The Romney campaign issued a statement Wednesday saying that Mitt and Ann Romney would love to visit the daytime talk show in October, but the Obamas beat them to it Thursday.

In the now famous recording of his May speech to a $50,000-a-plate fundraiser in Boca Raton, Romney describes “The View” as “high-risk,” because most of the women who host the popular show are outspoken.

“If you can’t handle four sharp-tongued women, how are you going to handle the country?” Sherri Shepherd, one of the hosts, said Wednesday.

Emily Yahr contributed to this report.