When Herman Cain’s SUV pulled outside the American Enterprise Institute this morning, a school of reporters was waiting, and gave chase down the ramp of a parking garage. It was the beginning of what’s sure to be the most challenging day of Cain’s presidential campaign, following last night’s Politico story reporting that as CEO of the National Restaurant Association during the 1990s, he had to settle claims concerning “inappropriate behavior” with two female employees.

The AEI speech itself focused on his 9-9-9 tax reform plan, and the think tank prohibited attendees from asking about the Politico story during the question and answer session. When ABC’s Jon Karl asked him about it anyway, Cain hid behind this policy. Cain himself will appear on Fox att 11:15 am, and is scheduled to attend a 12:30 luncheon at the National Press Club. So he’ll be forced to address the story.