Progressives are sounding the alarm ahead of President Obama’s upcoming speech on deficit reduction and entitlement reform. No one knows exactly what argument Obama will make in response to Paul Ryan’s 2012 budget proposal unveiled last week, but Jonathan Cohn foresees an opening negotiating stance too close to the center for his liking.

I feel like I’ve seen this play before. Obama starts off with a flexible, center-left position. The Republicans start off with a rigid, far-right position…The two go back and forth, eventually reaching a compromise that is somewhere between the two ideological starting points–which is somewhere on the right.

There is a time to bring opposing parties together. And there is a time to choose sides. I hope Obama realizes this is one of the latter.

In a subsequent post, Cohn predicts that on in Wednesday’s speech, Obama will propose raising taxes on the rich and strengthening cost control provisions in the Affordable Care Act. But what Cohn would really like to see is the president suggest far-left reform’s to balance Ryan’s proposal to end transform Medicare into a private system and severely cut funding for Medicaid. Says Cohn: