This makes the point.
McCain Ups Ante, Calls Paul, Cruz 'Wacko Birds'
McCain, who hit the Senate floor Thursday to belittle Sen. Rand Paul's filibuster, which succeeded in getting an answer from President Obama that drones won't be used to kill Americans on U.S. soil, even suggested that the Kentucky senator and his allies, like Texas Sen. Ted Cruz and Michigan Rep. Justin Amash, don't represent the GOP mainstream.
http://www.realclearpolitics.com/2013/03/09/mccain_ups_ante_calls_paul_cruz_039wacko_birds039_303594.html