The survey finds Trump with 45 percent support and Clinton with 40 percent.
“Bernie is doing more than attracting large crowds,” a spokesman said.
He says the U.S. should offer to take in at least 65,000 of the refugees by 2016.
Rebecca Shabad 09/04/15 01:41 PM EDT
Cruz plans to send the letter to Mitch McConnell early next week.
Rubio said Hugh Hewitt's questions to Trump were fair.
"I’m sorry this has been confusing to people," she said.
The former secretary of State has not had such low numbers since 1992, Gallup says.
"The time to put pressure on them is now," the 2016 candidate said.
Jindal hit at Trump after the front-runner said Ky. clerks should issue marriage licenses.
The ad blitz comes as Biden mulls a run and Sanders gains in some polls.