Rick Santorum on Tuesday made his most convincing argument that the electoral race to challenge Barack Obama is becoming a two-man contest.

With victories in Mississippi and Alabama, states where front-runner Mitt Romney also campaigned hard and where Newt Gingrich had all but vowed a last stand, Santorum walked away with small, if clear, victories.

With almost all of the precincts reporting, Santorum had a roughly 5-point victory over Gingrich in Alabama. Romney came in .3 points further back in third place. In Mississippi, again with almost all precincts, Santorum had a 1.5 point lead over Gingrich. Romney was 1 point further back.

“We did it again,” Santorum said to The New York Times. “The time is now for conservatives to pull together.”

But there was good news for Romney as well. With the victories being so tight, coupled with his own victories in the whee hours of the morning in Hawaii and American Samoa, Romney actually picked up the plurality of the available delegates. According to the Times, Romney gained 43 delegates, pushed ahead by the nine delegates awarded to the winner in American Samoa.

Santorum got 36 delegates, Gingrich 12 and Ron Paul, who had a particularly poor night, picked up 1 in Hawaii.

Romney still enjoys a commanding lead in the delegate count overall, with 495 delegates to Santorum's 252 and Gingrich's 131 and Pauls' 48.

More than 27 states have awarded delegates as of Tuesday, though a little more than half of the total delegates remain available. But what remains to be seen is how Gingrich will react to his disappointing second-place finish.

"“The elite media’s efforts to convince the nation that Mitt Romney is inevitable just collapsed,” Gingrich said to a crowd of supporters in Birmingham, according to the Times.. “If you’re the front-runner and you keep coming in third, you’re not much of a front-runner.”

Where the campaigns go from here remains to be seen. Most immediately, there's a Missouri caucus on Saturday, Puerto Rico's election on Sunday and Illinois on Tuesday. But the rest of the race will be defined in part at least on wheter Gingrich chooses to keep competing, depsite being virtually out of likely victories, or to concede and throw his support behind Santorum.

If that were to occur, Romney could see the stiffest challenge yet mounted to his front-runner candidacy.