The 2012 Republican presidential campaign — both nationally and in the state of Iowa — has been defined in large part by a series of boom/bust cycles by conservative candidates.

Minnesota Rep. Michele Bachmann boomed in Iowa over the summer then busted when Texas Gov. Rick Perry entered the contest. Businessman Herman Cain surged earlier in the fall only to bust — badly — amid allegations of sexual harassment.

Former House Speaker Newt Gingrich’s boom was cast by many as the final one of the race, coming, as it did, with the Iowa caucuses rapidly approaching.

And yet, Gingrich already appears to be on the down side of the boom-bust cycle with a week left to go before the Iowa caucuses. In fact, Gingrich’s growing and receding support seems to be following a very familiar pattern.

Check out this chart from the good folks at Real Clear Politics that looks at the breadth of polling down throughout the Iowa race. It’s a chart that should make Team Gingrich grimace.