Following Senator Harry Reid’s allegations that Mitt Romney has not paid taxes in over a decade, Anderson Cooper spoke with Paul Begala and Mary Matalin on tonight’s AC360°. Begala defends Reid and says there's evidence of "tax avoidance." Mary Matalin says it's sad that the Democratic Senate Majority Leader is leading the charge.

In April, President Barack Obama signed a bill that would ban insider trading on Capitol Hill. The measure, known as the STOCK Act, had passed the House and Senate at warp speed. But CNN’s Dana Bash and Deirdre Walsh uncovered that the law that members of Congress thought they voted for earlier this year isn't exactly as advertised. A loophole could still allow family members of some lawmakers to profit from inside information.

Following Bash’s exclusive report a few weeks ago, the U.S. House of representatives changed the stock reporting requirements today for families of lawmakers.

Tonight Anderson Cooper will interview Senator John McCain about the situation in Syria, Kofi Annan's resignation and President Obama’s secret authorization to assist the rebels there.