The short answer is “Sometimes.”
The longer answer is to be found in the Congressional investigation into Fannie/Freddie internal accounting. Net:net result? Freddy/Fannie don’t follow GAAP practices, they’re not following their own stated reasons for existing, they’re holding onto far too much paper themselves, distorting the markets, etc.
Fannie is to the Democrats what Enron was to the GOP. The difference is that Enron was like a 1 to 2” stone in the road, whereas Fannie could be like trying to drive over a cinderblock in the road.