Thanks to fladem for this historical perspective on late shifts in Iowa caucus-goers’ preferences. If you missed his earlier posts, check out A deep dive into Iowa caucus History and Iowa polling 45 days out: Let the buyer REALLY beware. -promoted by desmoinesdem

This is a continuation of an article I wrote about Iowa polling in November. At the time I noted how unpredictable the Iowa caucuses are. This article will to look at the last 48 hours. There are two lessons you can draw:

1. Front-runners beware

1. Expect someone to come from nowhere

The White House and key Democratic senators, including Iowa’s Tom Harkin, appear to be walking into a trap for the sake of bipartisan agreement on health care in the Senate.

There is growing support for a fake “public option,” as opposed to a government health insurance plan that would compete directly with private insurance companies.

If Congress passes this kind of deal and President Barack Obama signs it, we will get a enormously expensive non-solution to an enormous problem, and Democrats will pay the political price.

After the jump I’ll explain why political hacks as well as policy wonks should refuse the latest efforts to derail the public option.