With voting for the Republican presidential nomination starting in three holiday-shortened weeks, the dynamic for the 2012 election is becoming clear. President Obama is facing both formidable challenges but also significant advantages. The Republican nominee will too. But what promises to be a hard fought, close, general election may shift decisively to the president’s advantage depending on whom the Republican Party ultimately chooses as their nominee.

The general election environment poses daunting obstacles for the president. Economic growth is tepid, unemployment high, wages stagnant, deficits unsustainable, and the environment in Washington as toxic as ever. A significant number of voters don’t like the direction the country is going, are pessimistic about the future, and rate the president’s job performance below the 50% threshold that normally indicates electoral vulnerability.

But the president also has several important points in his favor. Voters like him personally, know he inherited many of our problems, and see him as being on their side and more willing to make reasonable compromises than his congressional opponents. The Electoral College has a slight Democratic tilt, and most of all, the lack of a primary opponent allows him to focus like a laser on the key independent, moderate voters who will decide the election while his future opponent must spend the next several months catering to the party faithful.

Under these circumstances, 2004 offers a template for a successful Obama re-election. His campaign must make the race a choice between two individuals not a referendum on the incumbent. He must energize the party base while disqualifying his opponent as an acceptable alternative for swing voters.

President George W. Bush adopted this approach and won a majority of the popular vote in 2004 even though only 48% of voters approved of his performance in office.

This strategy, of course, will be greatly impacted by the Republicans’ choice of nominee. The more target rich the standard bearer, the more likely Democrats’ success. At the moment, Republican primary voters seem poised to play into Democratic hands.

Mitt Romney has trouble inspiring Republican primary voters. This may be partly because of personal style, but also because of his past positions on health care, abortion, and other issues. But the fact that he’s a man of even temperament with a less dogmatically conservative record makes him easier to elect in the fall.

Newt Gingrich presents the opposite: the former House Speaker is more appealing to the party faithful, a man of many talents, but he's also political piñata for Democrats’ to attack.

We have seen the current front runner’s leadership in action before. -- It ended badly for Republicans.

In 1995, conservatives and congressional Republicans were riding high. A Democratic president was on the ropes. Republican control of both majoritarian branches was within reach. But maladroitly led by Speaker Gingrich, the newly emboldened right over reached. The government was shut down – twice. Withering battles over cuts to Medicare, Medicaid, education, and the environment alienated independents. The moment of opportunity was lost, and Bill Clinton was handily re-elected.

The former Speaker’s style contributes to his problems. His self-confidence projects strength but without discipline it can tend toward hyperbole and grandiosity, off-putting to moderates who prefer steady predictability. His intellect is impressive but also insufficient. Empathy – a trait he does not exude – is equally important. Finally, his penchant for self-immolation and major  missteps is well documented.

All of this isn’t to say that Newt can’t win. He has already defied predictions of his imminent demise, and his perseverance in the face of adversity and criticism is admirable. But his nomination would make Democrats’ chances much brighter in 2012. His election would require a renewed American economic slump and a personal transformation rarely seen in a public figure his age.

In 2010, Tea Party insistence on ideological purity and anger with President Obama led Republicans to nominate seriously flawed Senate candidates in Delaware, Nevada, Colorado and Alaska. The result? Republicans may have preserved Democratic control of the Senate.

The assent of Donald Trump, Michele Bachmann, Rick Perry, Herman Cain, and now Newt Gingrich show that Republican primary and caucus voters may do the same with the presidency in 2012.

Bottom line: Republicans have a choice. Is the nomination primarily about winning, governing and setting policy? Or is it primarily about venting anger at President Obama and maintaining ideological purity? Evidence suggests they may choose the latter -- making Christmas all the merrier this year for Democrats.

Evan Bayh represented the state of Indiana in the U.S. Senate from 1999-2011 and served as the 46th Governor of Indiana from 1989-1997. He is a Fox News contributor.