Protection of this nation from the insidious importation of terror under the guise of poor, despondent refugees. States must prosecute their authority as expressed by the Constitution
Chastising and threatening governors with temper tantrums is all the power the president wields in attempting to force states to accept refugees whose numbers are likely riddled with terrorists. And the House of Representatives isn't catering to the snarky attitude either, having just passed a bill to place a hold on acceptance of refugees from Syria with a bipartisan, veto-proof majority. How this issue goes forward depends on the willingness of the Senate to follow suit.
The gubernatorial standoff with the president accelerated after the conference call where Obama refused to offer any information regarding plans for refugee resettlement in their more than 30 states--against the law (USC VIII, Chapter 12, §1522 noted below1).