Celebrating business and hard work on opening night in Tampa

The Republican National Convention opened in prime time Tuesday night, with speakers emphasizing their belief in the free enterprise system and the ingenuity of American workers.

In speeches, and even a song, "We built it" was used as both a rallying theme and an attack line against President Barack Obama.

"President Obama just doesn't get this. He can't fix the economy because he doesn't know how it was built," said House Speaker John Boehner.

PolitiFact has put the "you didn't build that" controversy to the Truth-O-Meter. We rated the charge that Obama told business owners they didn't create their own enterprises False. (He was talking about government infrastructure that businesses rely on.)

Former Pennsylvania Sen. Rick Santorum embraced another Romney claim, telling the convention audience that Obama waived "the work requirement for welfare." We've examined that claim too and determined that it's a drastic distortion of the changes Obama proposes in welfare. The rating: Pants on Fire.

Ted Cruz, the Republican nominee for U.S. Senate in Texas, mentioned his eldest daughter in his speech to make a point about the rising national debt.

Cruz said the debt -- $10 trillion when his daughter, Caroline, was born -- had spiked to $16 trillion as of today, "larger than our gross domestic product." PolitiFact Texas dug into the numbers and rated the claim Half True.

Artur Davis, a former Congressman from Alabama, touched on a topic that's always a winner among Republicans: Obamacare.

"In terms of their crown jewel legislative achievement: Who knew that when asked, ‘Could  government conceivably impose a federal mandate requiring middle-class Americans to buy health insurance whether they can afford it or not?’ That the Obama answer would be ‘Yes we can!’ " said Davis, who endorsed Obama in 2008.

The comment made it sound like the law is indifferent to issues of affordability. That’s hardly the case. We rated the claim Mostly False.

New Jersey Gov. Chris Christie, the convention's keynote speaker, continued with the message that the U.S. is on a fiscally unsustainable path.

"With $5 trillion in debt added over the last four years, we have no other option but to make the hard choices, cut federal spending and fundamentally reduce the size of this government," Christie said.

We checked his math and arrived at a rating of Mostly True.

Christie focused some attention on his own state, claiming "taxes were raised 115 times in the eight years before I became governor," and those increases were part of a "path that led to wealth and jobs and people leaving our state." But Christie erred in calling all those increases "taxes." (Many were fees or other tax policy changes.) And there are multiple factors behind losing jobs, wealth and residents, such as the general downturn in the economy. We rated the statement Half True. His statement that he balanced the state budget with an $11 billion deficit earned the same rating.

Finally, we checked an offering from Minnesota Rep. Michele Bachmann, who told Fox News that a new government report "says the president's policies will drive up unemployment." The study she cited did not examine Obama's policies. Our call: False.