Sen. Rand Paul (R-Ky.) barely acknowledged his party's presidential candidate in his Republican National Convention speech, but he did adopt the campaign's increasingly central theme: "You built that." 

He began his speech by declaring President Obama's health-care law was unconstitutional, regardless of what the Supreme Court said. 

"Do you think Justice Scalia and Justice Thomas have changed their minds?" he asked. "I think if James Madison himself were here today ... he would agree with me: the whole damn thing is still unconstitutional."

And he argued that electing Mitt Romney was the only way to rectify the Court's error: "So, how do we fix this travesty of justice? There’s only one option left. We have to have — a new president!" 

The rest of his speech was devoted to President Obama's "you didn't build that" comment. Unlike many Republicans, Paul acknowledged the context of the president's words -- that infrastructure helps business thrive -- but rejected it. "Without the success of American business we wouldn’t have any roads, or bridges, or schools," Paul said.  

Read the full speech here.