In politics, as with most of life’s undertakings, effort is a necessary but not a sufficient condition for achievement. No man or woman, no matter how privileged or lucky the circumstances, has ever achieved greatness in the eyes of history without demanding great exertion from himself or herself.

That said, there really is such a thing as wasted effort, especially when it comes to trying to become president of the United States.

Mitt Romney is popular among many Republicans who viewed John McCain as a poor choice in 2008. However, the health-care debate has increased scrutiny of his record as governor of Massachusetts and eroded his Conservative credentials.

Furthermore, while race and gender have largely ceased to be serious electoral handicaps, virulent anti-Mormon prejudice survives among a broad swath of the American population, ranging from devout evangelicals to radical atheists. This is unjust, but it dooms a Romney candidacy.

Mike Huckabee appeals to evangelicals annoyed with McCain, but his populism also irritates free-market Conservatives and Independents. Even if he wins the nomination, he’ll likely find himself unable to turn his considerable political skill and loyal but narrow base of support into a viable general-election campaign.

Sarah Palin has been much vilified in the press for the most petty of reasons; despite her speaking style and family dramas, she remains a smart person with a decent policy record.

That’s not to say, however, that she is a viable contender for the presidency. Most notably, her premature resignation as governor of Alaska suggests a fundamental lack of seriousness that would turn off many Republicans were she ever to seek the nomination.

Some leftists in the media — most notably Keith Olbermann ­— have bandied around the idea of a Hillary Clinton primary challenge against Obama in 2012. She may also harbor ambitions to run in 2016, but by then Clinton will only be remembered by those who dislike her and any attempt at the presidency will almost certainly end in failure and obscurity.

For Democrats to dump their incumbent in 2012 would be a shocking break with historical precedent. No matter how much of an epic failure his administration is, Obama himself will retain sufficient personal popularity among Democrats to hold onto the nomination. The New York Times could report that Obama is a man-eating zombie pirate and Clinton would still lose to him in the primary.

Lou Dobbs, an Independent who recently quit his job as a show host on CNN, is rumored to be considering a run for president after remarks he made during a radio interview with Washington, D.C.’s WTOP. Dobbs opposes illegal immigration, gun control, tax cuts and free trade, while supporting abortion, gay rights and minimum-wage hikes. In other words, Dobbs’ platform is crafted to appeal to one man: Lou Dobbs.

Finally, Michael Bloomberg, the Independent mayor of New York, should also forget any presidential ambitions he may have. His support for free trade and clashes with unions as mayor would alienate Democrats, and his poor fiscal record and social liberalism make him unappealing to Republicans.

Finally, as a Wall Street Journal feature noted, the New York mayoralty is “America’s ultimate dead-end job” for a host of other reasons.

None of this is to say that Obama can’t be beaten in 2012, or that the field of candidates on both sides won’t change dramatically by 2016. But many of the names being batted around on both sides today aren’t worth considering.

Reach columnist Russ Wung at opinion@dailyuw.com.