But what is it about this right-wing libertarian that inspires such devotion among his followers - and such fear among many mainstream Republicans?
He has political views far to the left of most mainstream Republicans.
The effect, in the end, was to strengthen Lincoln's candidacy among mainstream Republicans.
Carole Shields, president of People for the American Way, a liberal group, said, "Moderate and mainstream Republicans have got to wonder where to turn."
Mr. Domenici was seen by his supporters as a more mainstream Republican who wanted to increase the party's outreach to women and Hispanics.
But mainstream Republicans cheered the appointments.
But even mainstream conservative Republicans (let alone the virtually extinct species known as moderate and liberal Republicans) are currently on the defensive.
But when mainstream Republicans were added to the list, the Governor dropped to near-even with Mr. Edwards.
These mainstream Republicans are justifiably outraged.
In the United States, states' rights has become a powerful policy goal among mainstream Republicans.