Today, Vice President Joe Biden held a fundraiser for Sen. Durbin’s 2014 re-election campaign.

I wasn’t there and most likely you weren’t either. The “cheap seats” cost $2,500, but tickets ran up to $37,600.

I have a pretty good idea, though, of who did attend. For CEOs at places like Citibank or CME Group, the luncheon is place to buy influence.

And Durbin, a leading Democratic mouthpiece for the corporate elite, is a prudent investment. He repeatedly speaks of his willingness to cut Social Security, a policy endorsed by Fix the Debt, whose members are America’s most powerful CEOs.

The proposal is a great deal for CEOs, who want to avoid a conversation about the taxes they aren’t paying, but it has dire consequences for seniors. The proposed cuts would cost the average senior $650 out of the $15,000 they receive annually (a number far smaller than the cost of many seats at today’s luncheon).

Durbin’s strategy ensures that his campaign coffers will be filled, but it undermines his past progressive leadership.

Next week, Sen. Durbin has invited Sen. Elizabeth Warren (D-MA) to stump for him. Warren, a real progressive, has made a well-reason case for expanding social security benefits, debunking the conservative talking points Durbin has been mouthing.

Instead of merely cashing in on Warren’s populist appeal, Sen. Durbin should join her call to expand social security benefits. Not only would that make his next lunch far less awkward, it’s what a progressive champion for Illinois would do.

Note: This letter originally appeared in the print & online edition of the Chicago Sun-Times on 26 Nov, 2013.