In the wake of the bloodiest terror attack on American soil since 9/11, Marco Rubio and Lindsay Graham are pushing for more Syrian terror to come on American shores.
Ted Cruz and Rand Paul both said no, but the Senators Graham and Rubio joined with the democrats.
Breitbart reports the political nuances:

A pivotal vote on Muslim immigration split the Republican presidential field in the Senate—with

Sen. Lindsey Graham (R-SC)



Sen. Marco Rubio (R-FL)


voting to continue to allow large-scale Muslim immigration and Senator

Sen. Ted Cruz (R-TX)



Sen. Rand Paul (R-KY)


voting to pause Muslim immigration.

The amendment, offered Sen. Rand Paul, would have suspended visa issuances to more than 30 Muslim countries with active Jihadist populations. Graham and Rubio were both members of the Gang of Eight, which proposed legislation that would expand Muslim immigration, and Paul and Cruz were both opponents of the Gang of Eight bill.
Graham and Rubio’s vote against curbing Muslim migration follows the attack in San Bernardino. The male suspect, Syed Farook, is the son of Pakistani immigrants; and the female suspect, Farook’s wife, Tashfeen Malik, was a Pakistani native. According to CNN, the two met, “when he [Farook] had gone to Saudi Arabia in 2013 on the Hajj, the annual pilgrimage to Mecca that Muslims are required to take at last once in their lifetime. It was during this trip that he met Malik, a native of Pakistan who came to the United States in July 2014 on a ‘fiancée visa’ and later became a lawful permanent resident.”
Sen. Paul’s amendment failed 89-10, with only nine other Senators joining Paul’s bid for a halt to the large-scale distribution of visas to nations with jihadist populations. The nine others supporting Paul’s amendment were
Sen. Jeff Sessions (R-AL)

Sen. Mike Lee (R-UT)

Sen. David Vitter (R-LA)

Sen. John Barrasso (R-WY)

, Mike Enzi,
Sen. Mark Kirk (R-IL)

Sen. Jerry Moran (R-KS)

Sen. Richard Shelby (R-AL)

and Senator Ted Cruz.
Majority Leader
Sen. Mitch McConnell (R-KY)

, Republican Whip
Sen. John Cornyn (R-TX)