Rand Paul's assessment of disability claim abuse is off in terms of degree (it's not half of SS claimants).  But the phenomenon he's describing is very real.  Having seen this close up, and having known people with serious disability claims who had to fight to get and keep them because the system is clogged with fraudulent claims for dubious maladies (bipolar, fibromyalgia, anxiety disorder, etc.), it's pretty cool someone finally had the balls to touch this third rail issue: 
http://www.cnn.com/2015/01/14/politi...ul-disability/
In 2008-2010, when the safety net was needed, suddenly claims were all rubber stamped by the govt.  Previous scrutiny was abandoned.  Then in 2011, when the SS disability program was criticized for having been lenient, and acting as a stealth welfare/unemployment avoidance device, claims became difficult again.  The problem, however, is those rubber stamped claimants didn't just go away.  Once on SS disability usually means permanently on it.  
I've seen guys with serious heart ailments held up in the claims process, simply because the backlog is so enormous.  While people claiming depression and anxiety and amorphous "general pain disorder" have gotten benefits due to luck of timing.  There ought to be an across the board audit and every claimant asserting anxiety or mild bipolar disorder (another favorite) be removed from the rolls. Docs backing up these dubious anxiety and bipolar claims ought to be subject to investigation by state medical boards.  (It's always the same guys, giving these same diagnoses, with near identical language in each of their records.)
Of course, his comment appearing mean to perceived down on their luck sorts, Paul is being attacked for it.  
End rant here.