GOP pros: Trump's third-party threat is probably an empty one. Probably.

Having considered these factors, Republicans appear widely to have decided it best to not take Trump’s threat seriously. Underpinning this conclusion is a sense among Republicans that Trump, while certainly wealthy enough to fund a third-party bid, would not ultimately have the stomach for such a herculean undertaking. Even if ballot access and funding were not at issue, the campaign would almost surely be a losing one.

“I don’t think he wants to spend half a billion dollars or more nor deal with the logistics to run a serious outsider independent campaign,” said one strategist for a competing Republican campaign. “So the only reason he is contemplating it is either (as an) empty threat, or he is a stalking horse for Hillary.”

Republican donor Fred Malek echoed to the Associated Press recently, “He’s a businessman who will look at his potential for winning and decide it will be a poor return on his investment.”

Assuming that Trump would not follow through with plans to run a third-party campaign comes with profound risk for Republicans. Were Trump to run as an independent, his candidacy would almost certainly have a Ross Perot effect: taking votes away from the Republican nominee and helping lift the Democratic candidate to victory.