The list of things a presidential candidate must do to have a realistic hope of winning the White House is long and complicated.
Among the things on that to-do list are:
• Raising vast amounts of campaign cash -- literally hundreds of millions of dollars these days.
• Going from state to state and city to city, tirelessly making the case to voters for why the candidate should be our next commander in chief.
• Presenting to the public the candidate's ideas on everything from national defense to job creation to environmental regulations.
But in the midst of that exhausting effort, the candidate must walk a fine line between standing up for his most cherished principles and trying not to alienate those who may not entirely agree with his views.
The balance is between revving up a candidate's partisan base and trying to reach out to voters who are on the fence, weighing the competing positions of the Democrat and Republican hopefuls.
In fact, it has become clear in recent years that a candidate is almost certain to lose the presidential election if he does not attract a high number of independent voters. It simply isn't enough to get a solid turnout from the voters in one's own party.
And that suggests that President Barack Obama could be in serious trouble in the 2012 election.
It's true that the election is still more than a year away, and a lot can change in that time. Things well beyond the control of the president or of the Republicans who are seeking the nomination to challenge him could alter the political scene in ways that no one can predict.
Nonetheless, it is apparent that Obama is losing a good deal of support from the independent voters he desperately needs if he hopes to win re-election next year.
A recent McClatchy-Marist poll of more than 1,000 people found that independents intend to vote against Obama in 2012 by an astonishing margin of 53 percent to 28 percent.
And while 36 percent of the people surveyed said they definitely will vote for Obama, a much higher 49 percent said they definitely will vote against him.
As if that were not enough bad news for the president, his job approval ratings are also extremely low. The poll found that public approval of the job the president is doing has sunk to 39 percent, and three out of four respondents said our nation is on the wrong track.
The public's frustration is understandable, given current high unemployment and the weak economy in general. Some, though not all, of that economic pain is the president's fault, but it's likely that voters will not view him favorably if things have not begun to turn around significantly before Election Day next year.
So, does all that mean the eventual GOP challenger is a sure bet to defeat Obama?
Far from it.
Some of the top GOP contenders occasionally have polled higher than the president in head-to-head match-ups. But in other polls, he has remained ahead of them.
What should be obvious is that no matter whom voters select to challenge the president, there will be a difficult battle for the White House. Obama did not get elected president by being a weak campaigner, and he will not lose that position without a fight.
The time between now and the election will be many things, but it will not be a cakewalk -- for the president or his GOP challenger.