If all the other candidates were eliminated Rubio would take Trump. Not according to the Economist / YouGov poll of 2000 Americans. They paired several candidates against Trump and against one another and if Trump is going to lose it will be against someone who has yet to announce.
|Donald Trump||57%||Marco Rubio||43%|
|Donald Trump||60%||Ben Carson||40%|
|Donald Trump||57%||Ted Cruz||43%|
|Ted Cruz||55%||Marco Rubio||45%|