You can add Marco Rubio to the list of presidential candidates free-falling in the polls amid the summer of Trump, but he's far from the only senator having a hard time catching fire in the GOP primary.
The CNN/ORC poll released Thursday showed the Florida Republican fell 5 points in a month, to 3 percent, tied with the limping campaigns of Sen. Rand Paul of Kentucky and Carly Fiorina for seventh place. Sen. Lindsey Graham of South Carolina barely registered at 1 percent, tied with former Sen. Rick Santorum of Pennsylvania.
The support of Rubio, Paul and Graham combined matches the 7 percent for Sen. Ted Cruz of Texas, who has ridden the anti-establishment wave alongside Donald Trump.
Trump, meanwhile, has more than double the combined support of all four sitting senators and Santorum, with 32 percent in the poll, up 8 points in a month, with political newcomer Ben Carson surging to 19 percent in second place.
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