The 2012 presidential primary season has been one of the most memorable in recent history, with a constantly changing line-up of front runners and contest winners.

Over the last several months with 17 debates and nine primaries and caucuses later, the race has yet to be settled with the Republican nomination still up for grabs and the remaining candidates preparing for a fight right up until the convention in August.

By this time in 2008, Sen. John McCain was well on his way to become the de facto Republican nominee by amassing a stockpile of delegates that couldn’t be topped by his main challenger, former governor of Massachusetts Mitt Romney.

For the Democrats, it took President Barack Obama until April to really clinch the nomination, but Sen. Hillary Clinton didn’t end her candidacy until June.

Since Romney conceded to McCain in March 2008, he has been campaigning for the 2012 Republican nomination and in the summer, he was the front-runner and had the best chance of clinching the nomination and challenging President Obama, until Texas governor Rick Perry entered the race in Sept. 2011.

Instantly, Perry became the front-runner, but after a series of debate gaffes, awkward moments on the stump, amassing more “dislikes” on a YouTube video than Rebecca Black and after failing to gain any substantial percentage in early contests, he exited the race on Jan. 19.

While Romney thought it would be easy for him to get the nomination, a repeating theme in this primary is that Republican voters don’t seem to like him. They’ve flirted with almost every candidate who has declared that they’re running for the nomination.

Former Speaker of the House, Newt Gingrich topped national polls for a while, as did CEO of Godfather’s Pizza, Herman Cain. Romney received a challenge from Gov. Jon Huntsman in New Hampshire and is now having to position himself as a true conservative against former Penn. Senator, Rick Santorum – something many voters have a hard time buying into.

The current state of the primary has Santorum with four caucus and primary victories and 37 total delegates with Romney also winning four primaries and caucuses with 124 total delegates. Rep. Ron Paul has 27 total delegates and Gingrich has 38, after winning the South Carolina Primary.

Nate Silver, of the “New York Times” political blog “538” writes, “Mr. Romney has had deep problems so far with the Republican base, going 1-for-4 in caucus states where turnout is dominated by highly conservative voters. Mr. Romney is 0-for-3 so far in the Midwest, a region that is often decisive in the general election.”

A Public Policy Polling national poll of Republican voters from Feb. 11 shows Santorum on top with 38 percent, compared to Romney’s 24 percent.

An issue for Romney moving forward could be a reduced turnout in early voting states compared with 2008 and reporters are puzzled by the fact that Santorum is gaining social conservative ground during an election that was supposed to be all about the economy; an issue Romney has been hammering away at in every debate.

Going into late Feb. and early March contests, Romney needs to draw a line of electability, leadership, and economic prowess between him and Santorum. While Santorum needs to capitalize on his social conservative favorability, but also

show his qualifications regarding economic and foreign policy issues; he can win in the mid-west, but is he electable in other parts of the country?

As Santorum declared in his victory speech after winning the Missouri primary, he is the true “conservative alternative to Barack Obama.” He obviously believes he could clinch the nomination and with some decent fundraising numbers after three victories in Minn., Colo., and Mo., he looks to have longevity in the race for several weeks.

For Romney, labeled as a Massachusetts moderate by Newt Gingrich, convincing the base that he is a true conservative could be the biggest challenge he will face in this election cycle.