There was the following passage in the [New York Times' article](http://www.nytimes.com/2016/01/20/us/politics/donald-trump-sarah-palin.html?hp&action=click&pgtype&_r=0) that came under the headline, “Sarah Palin endorses Donald Trump, which could bolster him in Iowa”:

> 
> “As Mrs. Palin announced her backing, Mr. Trump stood wearing a
>  satisfied smile as she scolded mainstream Republicans as sellouts and
>  praised how Mr. Trump had shaken up the party. “He’s been **going rogue
>  left and right**,” Mrs. Palin said of Mr. Trump, using one of her
>  signature phrases. “That’s why he’s doing so well. He’s been able to
>  tear the veil off this idea of the system.”
> 
> 
> 

As I checked the meaning of “go rogue” with both Oxford and Cambridge online dictionaries, neither of them carries “go rogue” as an idiom. Whilst Urban dictionary carries the definition of “go rogue” as “to cease to follow orders; to act on one's own, usually against expectation or instruction. To pursue one's own interests.”

If I follow Urban Dictionary’s definition, does “Trump has been going left and right” mean he has kept going against expectations of the left and the right?

What does “He’s been going rogue left and right,” mean, and why “go rogue” is Mrs. Palin’s signature phrase? Is it so creative, impressive, and effective phrase as being called as a signature phrase?