Media Matters points out, other MSNBC shows have been spinning this story negatively, and, in fact, AARP actually gained 400,000 members and 1.5 million people renewed their memberships during the same time period:

The approximately 60,000 number represents members who specifically cited AARP's stance on the health overhaul debate in canceling their membership between July 1 and mid-August, Nannis said. He said that on average AARP loses some 300,000 members a month, but he couldn't say how many more members had quit for other reasons in that time period.

He said AARP gained some 400,000 new members during the same period and that 1.5 million members renewed their membership. Read on...

It doesn't take a genius to figure out that AARP has seen a net gain of 340,000 members during the health care debate this summer -- which should have been Chris Matthews' Big Number, but that's not sexy enough for him. MSNBC isn't the only source spreading the misleading numbers either -- and CBS got the ball rolling.