Republicans and their manly fake names

The last post about Dick Cheney got me thinking about His Evilness's assorted henchmen, and none of said goons loom as large in the American political landscape as Scooter Libby. That, in turn, got me wondering about why there are so many Republicans who choose to use as their name something more manly or dashing than their actual name. Consider:

"Scooter Libby," actual name Irving Lewis Libby
"Jeb Bush," actual name John Ellis Bush*
"Mitt Romney," actual name Willard Mitt Romney

What's the deal here? Why is it that Republicans, who always want to embrace the authentically American self, are so anxious to run away from their real names, instead giving themselves a more suitably masculine identity? Are they latter-day Gatsbys, running away from their real identities, instead choosing to hide behind a constructed self?

*In the case of Jeb Bush, it's kind of hilarious, because "Jeb" is short for John Ellis Bush. So when you say "Jeb Bush," you are actually saying "John Ellis Bush Bush."