During the 2008 presidential campaign, Barack Obama promised that "half of all cars purchased by the federal government will be plug-in hybrids or all-electric by 2012."

There are more of them now, but Obama's stated goal hasn't been met.

Here's a chart showing vehicle acquisitions by fuel type between 2006 and 2010, published by the General Services Administration, the federal office that oversees the federal vehicle fleet. Numbers for 2011 are not yet available.

The chart illustrates that the administration has made strides in diversifying its fleet.

Purchases of cars that run on E-85, an 85 percent ethanol blend, actually outnumbered purchases of traditional gasoline cars in 2010 for the first time, and the combination of the two oldest technologies -- gasoline and diesel -- accounted for less than half of all purchases in 2010. As recently as 2006, they accounted for 70 percent of all purchases.

But Obama didn't simply promise to move to alternative fuel sources for the federal fleet; he specifically said he would make plug-in hybrids or all-electric vehicles half of new purchases. By that measurement, he's nowhere near his goal. For 2010, hybrids and all-electric vehicles amounted to just under 10 percent of federal vehicle acquisitions.

We don't have the numbers yet for 2011 or 2012 -- and the president's promise did say his promise will be effective by 2012 -- so we won't rule this a Promise Broken yet. But it will be a tough climb getting to the 50 percent threshold for electric or plug-in hybrids in just two years. If he manages to do it, we'll rate it a Promise Kept, but for now, we'll rate it Stalled.