The morning after the 2008 election, The Onion did the best job of bringing some perspective to the year-long spectacle of the presidential election in "Black Man Given Nation's Worst Job":
African-American man Barack Obama, 47, was given the least-desirable job in the entire country Tuesday…In his new high-stress, low-reward position, Obama will be charged with such tasks as completely overhauling the nation's broken-down economy, repairing the crumbling infrastructure, and generally having to please more than 300 million Americans and cater to their every whim on a daily basis. As part of his duties, the black man will have to spend four to eight years cleaning up the messes other people left behind. The job comes with such intense scrutiny and so certain a guarantee of failure that only one other person even bothered applying for it.
I teach a presidency class at least once per academic year; in it I always ensure that we spend some time talking about the basic but often overlooked question of who would actually want this job. Aside from subjective benefits – prestige, attention, political power, a feeling of importance, getting to learn cool secrets, etc. – it's really not a very appealing job.
The pay is subpar compared to the alternatives available to anyone capable of being elected president. The president has no normal family life, and neither his spouse nor his children can go anywhere without heavy security. In the average month 500-1000 different individuals threaten to kill you, about 1% of whom are making an actual plan to do so. The president works 70 or 80 hours per week and is on call 24-7. Everything on TV and in the newspaper is about how terrible the president is, why everything he does is wrong, and why he has ruined the nation. In the modern era, 60% is considered an astronomically high approval rating, i.e. the best you can hope for is that only about 120,000,000 Americans will hate you and consider you an abject failure. The odds of leaving office as a "success" are virtually nil.
It's not surprising that we see people who could conceivably be competitive in a presidential election declining to run. Mike Huckabee was a nobody ex-governor in 2008 until he won the Iowa Caucuses. That success made him a legitimate contender for the presidency (although certainly not an undisputed favorite) in 2012. But it also made him a TV host to the tune of $500,000 annually for one show per week, a syndicated radio contributor for an undisclosed six-figure salary, a highly compensated public speaker, and a fixture among the select group of authors who can churn out 250 pages of empty crap every 8 months and have it sell a million copies. As Chris Wallace said in response to claims that Fox unfairly boosts certain GOP candidates who happened to be paid on-air talent, "I have a theory that in fact (Fox News makes) life so pleasant for these folks like Mike Huckabee, I'm not sure Mike Huckabee wants to go campaign. I think he loves what he's doing here at Fox."
Mike Huckabee, in short, has been seduced by the good life of the pundit class, the Beltway pros who get paid a lot to work very little – "work" in this case consisting of offering opinions that range from the obvious to the deliberately provocative to the inane. The part of him that wanted to be president for personal glory or to serve the country was gradually worn away by the allure of money and stardom. The only thing more seductive than the limelight is money, and people like Huckabee are increasingly offered both as alternatives to presidential politics.
Huckabee certainly isn't the only one. Al Gore, who could have run a very credible campaign in 2008, realized that writing books, spending time with his wife, making movies, appearing on sitcoms, and winning awards was a lot more appealing than dragging himself and his family through the mud again. Sarah Palin is a right-wing brand name par excellence, with $50,000+ speaking fees and million dollar advances on ghostwritten books. She appears before crowds of sycophants who adore her, which is probably as ego-rewarding as political power. Michelle Bachmann could get a six-figure job at any Christian right powerhouse she chooses, and Mitt Romney could hit the Board of Directors circuit without breaking a sweat.
In short, many of these people are vacillating about 2012 not only because Obama will be difficult to beat but also because there are so many private sector temptations. For Republicans in particular, with the conservatives' strong network of targeted media outlets, non-profits, and interest groups, the temptation is getting darn near overwhelming. Unless an individual has an ego that can only be satisfied by the presidency, choosing between a couple million dollars per year hosting a TV show or "writing" "books" and serving as president is no choice at all.
(PS: For a decent summary of what Huckabee's exit does to the GOP field see Chris Cillizza)