Republican Presidential Debate

Not typically, but they can usually guess with decent accuracy what is going to be asked.

CNN: "It's Incorrect To Imply That The FBI Said That It Can't Vet Syrian Refugees." A CNN fact check rated Ted Cruz's claim that "the head of the FBI has told Congress they cannot vet [Syrian] refugees" as "false," noting that "it's incorrect to imply that the FBI said that it can't vet Syrian refugees." The fact check explained the refugee vetting process, noting that refugees "undergo several screenings ... which involve multiple federal intelligence and security agencies" and that "Syrian refugees in particular go through additional screening":

FactCheck.org: FBI Director "Comey Didn't Say That The U.S. Intelligence Community 'Cannot Vet Those Refugees.'" FactCheck.org accused Cruz of "twist[ing] [the] FBI director's words" and debunked Cruz's erroneous claim. The fact check clarified that Comey told Congress he could not offer an "'absolute assurance that there's no risk'" but that he "didn't say that the U.S. intelligence community 'cannot vet those refugees.'" FactCheck.org concluded that "the refugee review process is lengthy and involves multiple federal agencies":

PolitiFact: "The FBI Director Never Said, As Cruz Claims He Did, That The Government 'Cannot Vet' Refugees." PolitiFact rated Cruz's claim "mostly false," explaining that the refugee vetting process "involves the FBI as well as the State Department, the Department of Homeland Security, the Department of Defense and other agencies." The fact check noted that Comey "never said that federal agencies 'cannot vet' refugees in as plain of terms as Cruz suggested," and that the process, which can "take up to two years," "is effective and has gotten more so in the past few years":

CNN: "There Is No State Department Policy Prohibiting Social Media Checks" And DHS "Also Allows Social Media Checks." CNN explained that Ted Cruz, Carly Fiorina, and Mike Huckabee each claimed that the Department of Homeland Security (DHS) was restricted from checking social media during the visa vetting process. CNN debunked those claims, writing that "there is no State Department policy prohibiting social media checks by consular officers," who are "free to check any and all publicly available information on an applicant, including their social media postings." CNN noted that DHS "also allows social media checks." The fact check further noted that "in recent months the U.S. has begun to take steps to review social media of visa applicants from certain countries":

AP Debunks Claim That DHS Didn't Look At Social Media Because They "Thought It Would Be Inappropriate." The Associated Press debunked Ted Cruz's claim that "We didn't monitor the Facebook page of the San Bernardino terrorist because DHS thought it would be inappropriate," clarifying that "The Department of Homeland Security has authority to look at social media such as Facebook when evaluating visa applications, and the agency says it does so in some cases." The fact check pointed out that "scrutinizing social media accounts of every visa applicant would dramatically slow the approval process" and that monitoring the San Bernardino terrorists Facebook pages may not have prevented the attacks:

AP: "Trump's Suggestion That Illegal Immigration Is Increasing At The Border Is Not Supported By Arrest Statistics." The Associated Press noted that "arrest statistics are widely regarded as the best measure" of the number of undocumented immigrants crossing the border into the U.S., and that "Trump's suggestion that illegal immigration is increasing at the border is not supported by arrest statistics and that 2015 border arrest statistics are actually at "a near 40-year low":

Washington Post: "Trump Is Ignoring Data That Illegal Immigration Flows Have Fallen To Their Lowest Level In At Least Two Decades." A Washington Post fact check explained that "Trump is ignoring data that illegal immigration flows have fallen to their lowest level in at least two decades." The fact check also cited Pew Hispanic Center's 2012 report on Mexican immigration finding "a sharp downward trend in net migration from Mexico":

Associated Press Debunks Paul's Claim That All Post 9/11 Terrorism Has Been Carried Out By Legal Immigrants. An Associated Press fact check debunked Paul's claim that "every terrorist attack we've had since 9/11 has been legal immigration," noting that one of the San Bernardino attackers was born in Illinois and the perpetrator of the Fort Hood shooting was "not only an American but an Army major":