There's no "could likely" about it. If Trump throws in as an indie, a landslide win for Hillary is assured. Now, that may be tantamount to a "see, I told you so" moral victory for some, but it does assure the country's slide to oblivion will continue unabated. Just so we all know what the consequences are.And it's no secret...Everybody knows that...
The only intelligent thing to do then is for every one to abandon those other politicians in the primaries and vote for Trump...
If they don't, they have no one to blame for Hillary except themselves...It's going to be Trump or Hillary...There are no other options...
Remember those old Errol Flynn movies when he would play Robin Hood and he would be having a sword fight with TWO VILLIANS at the same time? This is how it would be with Trump as a third party candidate. He would skewer both Hillary and the Republican at the same time. Teeheehee ;^)