| Republican groups fighting Donald Trump are trying everything to derail the frontrunner, including airing ads targeting Trump University. The program sold nearly 7,000 students on learning the billionaire's real estate secrets, but more than 150 former students allege it was a fraud. Three lawsuits have been filed. So how do Trump’s public claims about Trump University compare with what he said behind closed doors? Julianna Goldman reports in this CBS News investigation.