Des Moines, Iowa -- Yahoo News is out with a report that is not good for Bernie Sanders' campaign. If it's true, that is. See the update below. 

According to the story, Sanders campaign strategist complained vigorously when CBS vice president Christopher Isham announced changes to the plan for tonight's Democratic presidential debate. The debate is set to begin at 9 p.m.

Representatives of all three campaigns were on the call, and Yahoo anonymously quotes an aide to another campaign and someone else who was on the call.

CBS News announced early Saturday that it would push a segment of questions on foreign policy and security to the top of the debate in light of Friday night's attacks in Paris. Given that it's the biggest news of the day, the change seemed to make sense. Not, apparently, to Longabaugh.

From Yahoo:

Sanders strategist Mark Longabaugh lit into CBS vice president and Washington bureau chief Christopher Isham when the changes to the debate were detailed on the call. 

“It was a little bit of a bizarre scene. The Sanders representative, you know, really laid into CBS and basically … kind of threw, like, a little bit of a fit and said, ‘You are trying to turn this into a foreign policy debate. That’s not what any of us agreed to. How can you change the terms of the debate, you know, on the day of the debate. That’s not right,’” the staffer recounted. 

The campaigns of Hillary Clinton and Martin O'Malley apparently agreed with CBS.

Whether a change is being made is no in doubt. Politico reporter Annie Karni tweeted shortly before 8 p.m. -- an hour before the debate -- quoting, by name, Sanders campaign manager Jeff Weaver saying CBS caved and "we won."