A voice from the audience responded that there were no more tickets, and Romney replied: 'No tickets? Just storm in."
Gingrich seemed far less confident as he campaigned his way into the debate.
He unleashed an attack reminiscent of his rhetoric a month ago when he was being outspent heavily on television and falling sharply in the polls just before the Iowa caucuses.
He accused Romney and Restore Our Future, the independent group, of dishonest ads, and said, "This is the desperate last stand of the old order. This is the kind of gall they have, to think we're so stupid and we're so timid."
He later told reporters he decided to sharpen his criticisms after Romney released his tax returns. "Here's a guy who owns Freddie Mac and Fannie Mae stock," Gingrich said. "He owns a Goldman Sachs subsidiary, which is foreclosing on Floridians. And on that front he decides to lie about my career? There's something about the hypocrisy that should make every American angry."
Romney released his income tax returns for 2010 and an estimate for 2011 after declining to do so in South Carolina.
Gingrich, also under pressure, disclosed the consulting contract one of his firms had with Freddie Mac, the government-backed mortgage giant that played a role in the foreclosure crisis that hit Florida especially hard. It showed payments of $300,000 in 2006 for unspecified consulting services.
Romney has pummeled Gingrich in the days since, calling him an influence peddler and a lobbyist who was taking money from the very organization that was harming Floridians.
Associated Press writers Brian Bakst and Kasie Hunt contributed to this story.
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