"These are mass murderers who were Muslim and ... returned from Saudi Arabia."
Cruz says forces have "no mission, no plan to win."
Rep. Kevin McCarthy was commenting on a new presidential poll.
The 2001 opinion piece says Muslims were celebrating in Paterson, N.J.
"You look at our border — it is completely porous," said the 2016 hopeful.
Hillary Clinton says she would like to see Russia involved as much as possible.
Trump refutes suggestion his rhetoric could turn Muslims against United States.
"As a nation we must do more than just echo the phrase Black Lives Matter," he said.
The 250,000 figure is a "myth," the administration says.
The left-leaning survey finds 46 percent who say Trump would kill the mood.