I know a 3L dude who got an interview (so he probably had pretty good credentials) and when he got there, the interviewers just straight-up told him, "We're probably only going to hire clerks this year." I'm assuming the interviewers were just speaking for their component, but it's still a depressing story. This was around 2009-2011.
Two summers ago I went to the DOJ Honors/SLIP fair they held at Justice and spoke to the recruiting staff and that's basically what they told me. Of the class selected that year, she told me only 2 or so did not have clerkships. Not sure if she was talking about all the components or just the ones that I specifically mentioned I was interested in.