Thousands of conservatives are in Washington this weekend to hear the GOP presidential candidates make a pitch for their votes.

With the race in constant flux--a different candidate seems to be the frontrunner every other week--the Conservative Political Action Conference (CPAC) could be a make-it-or-break-it moment for any of them.

Rick Santorum, who bills himself as the purest conservative left in the race, could get enough of a bump from the movers and shakers at the convention that it transforms his newfound momentum into a nomination.

Mitt Romney, struggling to convince conservatives that he's one of them, is using the opportunity to put his conservative credentials on display in an attempt to win voters over. His speech could be a game changer--in either direction.

Newt Gingrich, vowing to stay in the race despite a dismal showing since his South Carolina win, will speak Friday afternoon. Gingrich has maintained that Super Tuesday, when Southern states begin voting, will put him back in contention, and will likely aim his speech at appealing to that segment of the country.

But even with a divided party, one unifying force will bring them all together this weekend: the determination to knock President Obama out of office.

After hearing all the speeches, those attending CPAC will make its conservative presidential pick Saturday night.