CNBC and MSNBC contributor Ron Insana says that Republican front-runner Donald Trump may drop out of the race for the White House before the November election.“Given his personality type, I think he is exhibiting signs of intense frustration that comes from the diminishing amounts of undeserved adulation he received during his primary run,” Insana writes . “That may very well lead him to simply take his ball and go home. That decision could be further accelerated by a GOP that is now having a rather serious case of buyer's remorse.”Real estate developer Trump received the votes of 1,542 Republican delegates during the primary elections, surpassing the 1,237 needed for the nomination. His campaign as a political outsider has resonated predominately with white voters whose top worries are the economy, national security and the national debt. Trump’s detractors describe him as a racist, sexist xenophobe.“Trump's presidential obituary has been written more than once, and prematurely,” Insana says. “But there seems to be a change in the air. His behavior is more erratic. Republican leaders appear to be backing away from him, fearing a voter backlash if they stand too close to someone who, until recently seemed only toxic, but may now be radioactive.”Politicians from both the Democratic and Republican parties this week pilloried Trump for his suggestion that U.S. District Judge Gonzalo Curiel cannot fairly preside over lawsuits against Trump University because of his Mexican heritage. Class actions targeting the now-defunct organizer of real estate seminars describe its methods as fraudulent and predatory.“His invective is taking on a new intensity as he struggles with the personal and political scrutiny that comes with being the party's standard-bearer,” Insana says. “It might be too much for even Trump to bear. He is accustomed to unflagging support, idol worship and winning.”Billionaire investor Carl Icahn this week told CNBC that Trump would make the best president."(Hillary) Clinton says she's there to clean up this mess, but she's been there all these years and hasn't done anything," said Icahn."We need a major change or we will see riots in the streets," Icahn predicted."It's no secret...there's pure gridlock [in Washington] and they can't get anything done," he said. Trump's "a consensus builder, he knows how to deal with people," said Icahn.Trump last year said if elected, he would name Icahn as Secretary of the Treasury. Icahn later said he's not interested in the job.