First, the origins of the word:
In the 1800s, Samuel Augustus Maverick went to Texas and became known for not branding his cattle. He was more interested in keeping track of the land he owned than the livestock on it, Ms. Maverick said; unbranded cattle, then, were called “Maverick’s.” The name came to mean anyone who didn’t bear another’s brand.
And then some history of how REAL "Mavericks" behaved:
“I’m just enraged that McCain calls himself a maverick,” said Terrellita Maverick, 82, a San Antonio native who proudly carries the name of a family that has been known for its progressive politics since the 1600s, when an early ancestor in Boston got into trouble with the law over his agitation for the rights of indentured servants...
Sam Maverick’s grandson, Fontaine Maury Maverick, was a two-term congressman and a mayor of San Antonio who lost his mayoral re-election bid when conservatives labeled him a Communist. He served in the Roosevelt administration on the Smaller War Plants Corporation and is best known for another coinage. He came up with the term “gobbledygook” in frustration at the convoluted language of bureaucrats.
This Maverick’s son, Maury Jr., was a firebrand civil libertarian and lawyer who defended draft resisters, atheists and others scorned by society. He served in the Texas Legislature during the McCarthy era and wrote fiery columns for The San Antonio Express-News. His final column, published on Feb. 2, 2003, just after he died at 82, was an attack on the coming war in Iraq.
Terrellita Maverick, sister of Maury Jr., is a member emeritus of the board of the San Antonio chapter of the American Civil Liberties Union of Texas.
“It’s just incredible — the nerve! — to suggest that he’s not part of that Republican herd. Every time we hear it, all my children and I and all my family shrink a little and say, ‘Oh, my God, he said it again.’ ”
“He’s a Republican,” she said. “He’s branded.”