But the course of the ’68 campaign should give the Romney Regiments reason for pause: despite disastrous divisions among the Democrats and a third-party candidacy by Alabama Gov. George Wallace that drew millions of typically Democratic blue-collar votes, Vice President Hubert Humphrey closed the gap dramatically in the campaign’s final weeks and came within a whisker of upsetting the heavily favored, overconfident Republicans. Nixon drew only 43.4 percent of the popular vote, besting Humphrey by seven-tenths of 1 percent…

The Herminator clearly lacks the national organization or campaign war chest to derail the well-oiled, lavishly funded Romney juggernaut, but his folksy, sympathetic personality and compelling debate performances should allow him to continue as a candidate, and as pitchman for his bestselling book, through the convention in Tampa. Cain also displays little inclination to destroy or discredit his opponents and thereby compromise the enormous reservoir of goodwill he’s accumulated. He can, in other words, serve Romney’s interests in much the same way Mike Huckabee served John McCain’s interests in 2008: providing a challenge that allows the frontrunner to sharpen his skills and enhance his stature without damaging the anointed winner with personalized or mean-spirited attacks…

And that leads to the second name Romney must consider to enable his campaign to escape Nixon’s shadow: Marco Rubio, the compellingly charismatic junior senator from Florida. Nearly all Republican strategists place Rubio at the top of the list as a potential running mate in 2012, and the Floridian’s youth, passion, peerless communication skills, and Cuban ancestry might provide a particularly effective complement for the cool, collected, soothing aura of the Mittster. Whether it’s Rubio, New Jersey’s Chris Christie, Cain himself, or some other high-energy shining star in the conservative firmament, Romney should select a vice-presidential nominee who adds pizzazz and electricity to the ticket.