(CNN) -- Mitt Romney got more good delegate news Thursday as the Republican presidential campaign headed toward next week's Super Tuesday showdown, with one candidate acknowledging he needs a victory to keep his campaign alive.
Former House Speaker Newt Gingrich, campaigning in Atlanta ahead of the Georgia primary on March 6, made it clear he has to win the state he represented in Congress.
"I have to win Georgia, I think, to be credible in the race," said Gingrich, who has won only one primary so far, in neighboring South Carolina.
Gingrich is vying with former Pennsylvania Sen. Rick Santorum to be the conservative alternative to the more moderate Romney in the race for the Republican nomination to face President Barack Obama in November.
Romney bolstered his delegate lead by winning in Wyoming, where Republicans held caucuses and cast votes in straw polls in recent weeks.
Based on results compiled and released Wednesday night by the Wyoming Republican Party, Romney won 39% of the votes cast in straw polls conducted at county-level caucuses, while Santorum got 32%. Rep. Ron Paul of Texas received 20% and Gingrich got 8%.
Of the 26 delegates at stake, CNN estimates Romney will pick up 10, while Santorum will take in nine delegates. Paul will receive six and Gingrich one.
In addition, Republican officials in Michigan announced Thursday they rejiggered the delegate allocation from Tuesday's primary to give Romney 16 of the 30 available, with 14 going to Santorum.
The change was because of an expected penalty against Michigan by the Republican National Committee for holding the primary earlier than desired, according to the Michigan Republican Party.
Romney won the popular vote, receiving 41% to 38% for Santorum, but the initial delegate count was 15 for each. That had given Santorum some bragging rights for holding his own in the state where the better-financed Romney grew up and where his father was governor.
Santorum's campaign accused Romney of engineering the delegate reallocation.
"We've all heard rumors that Mitt Romney was furious that he spent a fortune in his home state, had all the political establishment connections and could only manage a tie," spokesman Hogan Gidley said in a statement. "But we never thought the Romney campaign would try to rig the outcome of an election by changing the rules after the vote. This kind of back-room dealing political thuggery just cannot and should not happen in America."
CNN estimates that so far in the campaign, Romney has 182 delegates, Santorum has 79, Gingrich has 39 and Paul has 38. It takes 1,144 delegates to secure the nomination.
Romney also got a boost in Georgia on Thursday when the largest newspaper in Savannah endorsed him over Gingrich, calling Romney "the one GOP challenger who has the best chance of winning" against Obama.
"Newt comes with more baggage than a luggage carousel at Hartsfield-Jackson International Airport," the Savannah Morning News wrote of their state's own. "(W)inning enough states to beat Mr. Obama in a national election is the longest of long shots. That's because moderate, independent voters who tipped the balance Mr. Obama's way four years ago are unlikely to go Newt's way in November."
It concluded that "Georgia Republicans who want to win the White House should wake up and see the road map," adding that they may like Gingrich and Santorum now, "but if victory in November is the goal, Mitt Romney should get their support."
The Wyoming caucuses were Romney's third victory this week, after the former Massachusetts governor got much-needed wins in Arizona and Michigan on Tuesday.
Santorum, campaigning Thursday in Georgia, depicted himself as the candidate best able to energize support.
"Who would have the ability to go out and rally the American public?" Santorum said at a stop in Dalton. "Who would have the fortitude to stand up to the tough abuse that you are going to get from -- yes -- the media and from the left and even from those maybe even within your own party, and stand up and stay strong and have a record of showing you can stand for your convictions?"
In a sign of growing momentum, a Santorum campaign source told CNN that the former Pennsylvania senator will report raising $9 million in February from more than 130,000 contributors, and that Wednesday had been one of the campaign's best fund-raising days of the cycle.
Romney, campaigning in North Dakota, took aim at Obama, accusing the president of offering uncertainty rather than support for expanded energy production.
On Wednesday, Romney went after Santorum while campaigning in Ohio, another major battleground in next week's Super Tuesday showdown, when 10 states will hold contests.
"Rick Santorum is a nice guy, but he is an economic lightweight," Romney told a crowd at Capital University in Bexley, an affluent suburb of Columbus. "He doesn't understand what it takes to make the economy work on a personal basis."
Earlier, Romney said at a Toledo event that Republicans need a candidate from outside the Washington culture of Obama and the other Republican challengers.
"I just don't think we are going to beat Barack Obama and get our country back on track if we have guys whose resume looks like his resume," Romney said.
Tuesday's results were a relief for Romney, who needed to win both states, but especially needed Michigan to assert his ability to overcome the conservative challenge from Santorum.
A Santorum victory in Michigan would have raised questions about how strong a candidate Romney is within his own party as the campaign heads into a busy schedule of primaries and caucuses.
The 10 states holding primaries and caucuses on Super Tuesday have 437 delegates, with 419 of them to be allotted based on the results in those contests. The other 18 delegates are not tied to the results.
Other major states on Super Tuesday will include Georgia, Tennessee and Oklahoma, all traditionally conservative territory where Gingrich must do well to keep up his campaign's viability.
However, Gingrich's hope of building a strong support base in the South after his lone victory in South Carolina appears in trouble. Santorum holds a big lead in polls in Tennessee and Oklahoma, as well as Ohio.
The primary and caucus results continue to show that combining the support for Gingrich and Santorum generally equals or exceeds the support for Romney, who has been unable to increase his level of backing despite an advantage in money and organization.
On Tuesday night, Santorum said the Michigan outcome showed the Republican race was a two-person showdown between himself and Romney. That argument was intended to increase pressure on Gingrich to step aside so that Santorum can galvanize conservatives.
Gingrich indicated Thursday that, despite his need to win Georgia, he is disinclined to drop out.
"Part of why I am not going to back out is I think people deserve a chance to have a genuine conservative, and based on people donating across the country, I think they agree," Gingrich said.
He added that Romney "can't close the sale" despite spending far more than the other candidates so far.
"If he can't close the sale, our job is to go out and keep making the sale until we finish closing it," Gingrich said. "And as you see us get to more and more states, the narrative will become more and more that there is a real alternative."
Romney has led nationwide polls off-and-on over the course of the campaign, but has been unable to increase his support base. Santorum is the latest of Romney's rivals to challenge him for front-runner status by playing on conservatives' reservations about the former Massachusetts governor.
Santorum's hat trick last month in Minnesota, Missouri and Colorado propelled him to a lead in national polls and a double-digit lead in Michigan two weeks ago.
However, he had a lackluster performance in the CNN Arizona Republican debate and has fallen into a statistical tie with Romney in national polls.
Paul, the libertarian champion making his third bid for the White House, was looking to the Washington state caucuses on Saturday and Super Tuesday to try to increase his delegate count.
"We'll continue to work in the caucus states" where investments of time and resources pay off in delegates, Paul told CNN.
CNN's Ed Payne, John King, Keating Holland, Robert Yoon, Jim Acosta, Paul Steinhauser and Rachel Streitfeld contributed to this report