WASHINGTON - A White House official on Sunday launched a blistering attack on the federal appeals court that blocked President Donald Trump's executive order on immigration, calling its ruling a "judicial usurpation of power."The Trump administration has faced multiple legal setbacks to its travel ban issued on Jan. 27, and the Republican president has said he may issue a new order rather than go through lengthy court challenges."The president's powers here are beyond question," White House adviser Stephen Miller said on the "Fox News Sunday" program. He criticized the 9th US Circuit Court of Appeals ruling blocking the order. "The 9th Circuit has a long history of being overturned and the 9th Circuit has a long history of overreaching. We don't have judicial supremacy in this country."