San Diego, California (CNN) -- American humorist Will Rogers once said, "I'm not a member of any organized political party. I'm a Democrat." The old saying goes that, come election time, Republicans fall in line and Democrats fall apart. The tradition in the GOP has been that, if you ran for president and came up short -- Ronald Reagan in 1976, George H.W. Bush in 1980, John McCain in 2000, Mitt Romney in 2008 -- next time, it would be your turn. Among Democrats, it was a free-for-all. Hillary Clinton was thought to have a lock on the 2008 Democratic presidential nomination, but Barack Obama had other ideas.
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Ruben Navarrette: Traditionally, Democrats have been the party of internal feuds
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Now the Republicans seem badly split, with top figures sniping at each other, he says
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Chris Christie and Rand Paul traded barbs; Ted Cruz, Marco Rubio also attacking
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Navarrette: Republicans aren't demonstrating that they have presidential stature
Cruz continued that theme when -- in comments that got him in hot water with liberals and conservatives -- he accused fellow @placeholder of being part of a "surrender caucus" because of their reluctance to buck the tide.