( CNN ) -- Celebrity business magnate Donald Trump endorsed Mitt Romney for president Thursday , telling reporters he will not mount an independent campaign if Romney is the Republican nominee . Trump , who has repeatedly flirted with the possibility of his own White House bid , revealed his decision in Las Vegas two days before Nevada 's Saturday caucuses . `` It 's my honor , real honor , to endorse Mitt Romney , '' Trump said , with Romney and his wife standing nearby . Calling Romney `` tough '' and `` smart , '' Trump said , `` he 's not going to continue to allow bad things to happen to this country . '' Romney responded by praising Trump for `` an extraordinary ability to understand how our economy works and to create jobs '' and for being `` one of the few who has stood up to say China is cheating '' in international trade . It was unclear whether Trump 's decision will have any impact on the Republican race . A Pew survey last month found that 64 % of definite and likely GOP voters said an endorsement from the reality television star would make no difference to them . In the survey , 13 % said it would make them more likely to back a candidate , while 20 % said it would actually make them less likely . `` Endorsements rarely sway voters , '' Republican strategist Alex Castellanos said . But `` the Trump endorsement undermines ( Newt ) Gingrich 's argument that it is just the Washington establishment that is out to stop him and nominate Romney . Trump is the ultimate outsider . '' Trump was not always so positive regarding Romney 's record . During an interview on CNN 's `` State of the Union '' in April , Trump criticized Romney for eliminating jobs while in the private sector . `` He 'd buy companies . He 'd close companies . He 'd get rid of jobs , '' Trump told CNN Chief Political Correspondent Candy Crowley . `` I 've built a great company . My net worth is many many times Mitt Romney . '' Asked what changed since then to bring his endorsement of Romney , Trump told CNN later Thursday that his past comments were `` political talk . '' `` That was a long time prior to my getting to know him , '' Trump said of Romney . `` But I have gotten to know him and he 's a terrific guy . I do n't know if he really comes out like he really is in person . He 's a warm , smart , tough cookie and that 's what this country needs . We need somebody that 's tough , that will stop China and OPEC and all these other nations from just ripping us up . And i think he can do it . '' Perhaps in reference to Trump 's earlier comments , Romney said Thursday after thanking Trump for the endorsement , `` I spent my life in the private sector , not quite as successful as this guy but successful nonetheless . '' News of Trump 's endorsement of the Republican front-runner came as the GOP candidates stumped for votes across Nevada and Romney continued to wrestle with fallout from a CNN interview in which the former Massachusetts governor said he was n't `` concerned about the very poor . '' Poll : Romney 's big lead in Nevada . `` We have a safety net '' for the very poor , Romney told CNN 's Soledad O'Brien on Wednesday . `` If it needs repair , I 'll fix it . I 'm not concerned about the very rich ; they 're doing just fine . I 'm concerned about the very heart of America , the 90 % , 95 % of Americans right now who are struggling , and I 'll continue to take that message across the nation . '' Pressed by O'Brien , Romney noted that the poorest Americans have access to food stamps , Medicaid and housing vouchers . `` You can choose where to focus , '' he said . `` You can focus on the rich ; that 's not my focus . You can focus on the very poor ; that 's not my focus . My focus is on middle-income Americans . '' Romney later insisted that his words were taken out of context and reiterated the full context of the quote , which was meant to stress his focus on the middle class . `` You 've got to take the whole sentence , ( or else ) it sounds very different , '' he said . `` We have a safety net for the poor . ... If there are people that are falling through the cracks , I want to fix that . '' The comment , however , sparked a new round of debate over an emerging narrative of Romney as a plutocrat unaware of the needs and concerns of ordinary Americans . It also evoked memories of previous controversial Romney statements , such as when he said he likes firing people who provide poor service . Gingrich hammers Romney over 'poor ' comment . Romney is `` reinforcing the image of the national party that is elite ( and ) out of touch , '' said Mark McKinnon , a former campaign adviser to George W. Bush and John McCain . `` That 's why he 's having such problems with independent voters . ... Unless the Republicans turn that around , they can not win this election . '' Gingrich , the former House speaker , has blasted Romney for the remark over the past two days , declaring Wednesday that he is `` fed up with politicians in either party dividing Americans against each other . '' On Thursday , Gingrich said that `` we should care about the very poor -- unlike Governor Romney . But I believe that we should care differently than Barack Obama . Both Governor Romney and Barack Obama seem to believe that a 'safety net ' is all the poor need . I do n't believe that . What the poor need is a trampoline so they can spring up and quit being poor . '' Gingrich press secretary fights off Trump questions . Regardless of the extent of Romney 's verbal miscue , the former governor is now the clear Republican front-runner . A national poll released Wednesday showed an immediate benefit for Romney , putting him in first place at 31 % compared to 26 % for Gingrich , 16 % for Santorum and 11 % for Paul . The Gallup daily tracking poll had Gingrich ahead of Romney after the former speaker won the January 21 South Carolina primary . Romney cemented his status as the GOP leader with an overwhelming victory in Tuesday 's Florida primary . Romney won the primary with 46 % of the vote , compared with 32 % for Gingrich , 13 % for Rick Santorum and 7 % for Ron Paul , according to the Florida Department of State . The victory gave Romney all 50 of Florida 's convention delegates and , more important , new momentum heading into a series of caucuses and primaries building up to Super Tuesday on March 6 , when 10 states will hold nominating contests . Zakaria : Why I ca n't wait for the Republican convention . Gingrich 's campaign asked the Republican Party on Thursday to allocate the 50 Florida delegates on a proportional basis , rather than the winner-take-all format that gave them to Romney . In a letter to the Republican National Committee , the Gingrich campaign argued that an RNC rule says early primaries and caucuses must award delegates proportionally . However , party rules say the issue can be addressed only at the August nominating convention in Tampa , Florida . Santorum also has expressed support for Florida to change its system , but the Florida Republican Party chairman , Lenny Curry , said in a statement Thursday that wo n't happen . `` Florida was winner-take-all before election day , we were winner-take-all on election day , we will remain winner-take-all , '' Curry 's statement said , adding : `` It is a shame when the loser of a contest agrees to the rules before , then cries foul after losing . '' CNN 's Tom Cohen , Jim Acosta , Paul Steinhauser and Alyssa McLendon contributed to this report .
NEW : Trump said he previously criticized Romney before getting to know him . The value of a Donald Trump endorsement of Mitt Romney is unclear . Rick Santorum agrees with Newt Gingrich that Florida delegates should be proportional . The Republican candidates are campaigning in Nevada , which holds its caucuses Saturday .