So What Is a Maverick?

I keep hearing John McCain being referred to as a "Maverick", and now his running mate. Just Google "Political Maverick" and review the results. Wow, Washington is filled with Mavericks. I didn't really have a clear definition of Maverick so some quick digging turned up -

According to Wikipedia, a Maverick can be defined as: a person who shows independence of thought or action, a non-conformist or rebel.

JoinMaverick.com has several definitions:
n. 1. an unbranded calf, cow or steer
e.g., If we don't fix that fence, the mavericks will wander off and we'll never get them back.
2. a lone dissenter, such as an artist or politician
e.g., The writer was a real maverick — ahead of her time.
3. a leading technology company with a unique approach to engineering, business consulting and systems integration
e.g., MAVERICK Technologies has helped clients in a variety of industries reach new levels of profitability.

v. 1. to break away from limitations
e.g., It's time to maverick this business and see what we can achieve.

adj. 1. dissenting or expressing independent thought
e.g., The maverick thinker thinks outside the box and makes a difference in the world.

They note some famous Mavericks as:
Famous Mavericks

1. Sir Isaac Newton (164–1727)

Newton is most famous for defining his three laws of motion and the concept of gravity. His mother wanted him to be a farmer, but with the help of the headmaster at his school, Newton instead pursued his education and became one of the world’s greatest thinkers.

2. Sam Houston (1793–1863)

Sam Houston was president of the Republic of Texas, a Texas senator and eventually the state’s governor. In 1861 he was removed from office because he was one of the few opposing the secession of Texas from the Union.

3. Rosa Parks (1913–2005)

As the mother of the modern-day civil rights movement, Rosa Parks instigated the Montgomery Bus Boycott when she refused to give up her bus seat for a white passenger.

4. Jack Kerouac (192–1969)

The King of the Beats, Kerouac brought a unique voice to literature and mastered the genre of spontaneous prose. The Jack Kerouac School of Disembodied Poetics at Naropa University was founded in his honor, but he was not critically acclaimed until after he died.

5. Tasmanian Devil (1954– )

Known as a crazed loner with an insatiable appetite, Taz appeals to many cartoon lovers who also have a bit of a wild side.

According to this article in the New York Times, "Andrei D. Sakharov, the Nobel Peace Prize winning dissident, Boris N. Yeltsin, the deposed Moscow Communist Party boss"..."two of the country's most famous mavericks"

And lastly, Answers.Com tells us :"One that refuses to abide by the dictates of or resists adherence to a group; a dissenter." Further down the page it says:

"Although most members of Congress still follow the advice of Speaker Sam Rayburn (Democrat–Texas) that “to get along you have to go along,” a few senators and representatives made their career not by “going along” but by becoming legislative mavericks. Mavericks tend to represent a minority viewpoint within their own party and tend to refuse to bend their principles to prevailing attitudes. Mavericks are often showmen who enjoy the spotlight of publicity. They will employ disruptive tactics to stop or slow down action on a bill, trying to make the majority agree with their demands. They may show contempt for the rules, courtesies, and elaborate forms of politeness that other legislators adopt with each other."

Take it as you may but I suppose in our own right, everyone is a "Maverick" to some degree.