LAS VEGAS (CBSNewYork/AP)-- Donald Trump is railing against continued efforts by some frustrated Republicans planning a last-ditch effort to try to thwart him from becoming the party's nominee.

Speaking at a rally in Las Vegas Saturday afternoon, Trump referred to "a little movement'' "coming from people that have been badly defeated.''

Trump alleges the efforts are not legal and wonders who the party would pick in his place.

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He says, "I beat everybody,'' and "beat the hell out of them.''

Trump also says "it would be helpful'' if fellow Republicans would rally around him to help him beat likely Democratic rival Hillary Clinton.

The billionaire threatened that, if Republicans don't come together, he'll go back to funding his own campaign.

A new CBS News poll shows Clinton holding a six-point lead nationally over Trump in the presidential race.

The former secretary of state is up 43 to 37 percent of the presumptive Republican nominee. Last month, the presumptive Democrat nominee held a 47 to 41 percent over the billionaire.

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