NEW YORK (Reuters) - Ted Cruz, Donald Trump’s closest rival in the Republican race for the White House, named his national security advisers on Thursday, including former staffers of President Ronald Reagan and members of a think tank that has been called an anti-Muslim “hate group” by a civil rights organization. Announcing the team in a statement, Cruz said he would reverse what he described as the weakening of the United States in a dangerous world, singling out militant Islamist groups in the Middle East and North Africa as his focus. Among the most recognizable names on the senator’s list of 23 advisers was Elliott Abrams, who served in the administrations of both Reagan and President George W. Bush and is a senior fellow at the Council on Foreign Relations.  But the list of advisers drew more attention for its inclusion of several critics of Muslims. Among those were Frank Gaffney, a former official in the Reagan administration, and at least two other members of a think tank Gaffney founded, the Center for Security Policy. The center’s reports argue that hundreds of thousands of American Muslims support Islamist violence in the United States and that there is a conspiracy to erode the U.S. legal system by elevating sharia, the Islamic legal code. The Southern Poverty Law Center, a civil rights organization that monitors U.S. extremist groups, has labeled the Center for Security Policy a “hate group” and Gaffney a “notorious Islamophobe.” Gaffney did not respond to a request for comment, but a spokesman pointed to online essays where Gaffney has rejected such criticism, saying his group is a defender of civil liberties against “Islamic supremacists.” “Do you mention any of the other 22 members of the advisory coalition?” Brian Phillips, a Cruz spokesman, said in an email, declining to respond to questions about the criticisms made against Gaffney and his think tank. The Council on American-Islamic Relations (CAIR), a Muslim rights group, urged Cruz, a Christian, to reconsider having Gaffney and others who have made anti-Muslim remarks as his advisers, saying it suggested the candidate entertained “anti-Muslim bigotry”. Besides Gaffney and his think-tank colleagues, CAIR said Cruz should drop William Boykin, a retired U.S. Army lieutenant general who has said the government should be allowed to ignore the U.S. Constitution to pass laws limiting Muslims’ right to freedom of speech and religion. Some of Cruz’s other advisers have been critical of anti-Islamic rhetoric, including Abrams and Mary Habeck, another former Bush adviser; both have said Islam should not be demonized. Another adviser is Katherine Gorka, president of the Council on Global Security, a group that produces research on Islamist violence, who said in an email that Cruz “understands the vital role that America’s military strength plays across the globe but without wanting to engage the U.S. in expensive democracy-building adventures.” TRUMP-CRUZ SHOWDOWN Trump, a 69-year-old billionaire businessman from New York, has surged to the front of the once-crowded Republican field, drawing support from voters by proposing to temporarily ban Muslims from entering the United States for fear they might secretly be members of violent Islamist groups. Trump cited research by Gaffney’s group in announcing the plan last year. Cruz, a 45-year-old Texan, is seeking to keep Trump from winning an outright majority of delegates as states vote for party nominees in the coming months, and to wrest the nomination from him at the party’s national convention in Cleveland in July.  Conservatives who think Trump strays too far from Republican ideology continued to plot openly to thwart him at or before the convention.  Erick Erickson, a conservative blogger, said in a statement that he joined a meeting of “grassroots conservative activists” from around the country in Washington on Thursday. He said they made plans to appoint an as-yet-unnamed candidate at what they hope will be the first contested Republican convention since 1948, where a complicated system of ballot rules would come into effect. Earlier this month, Mitt Romney, the party’s unsuccessful 2012 presidential candidate, called on Republicans to use tactical voting to slow Trump. The call appeared to have been ignored by many Republican voters, with Trump remaining the leading candidate following the most recent round of primary elections on Tuesday. Cruz has said “everyone understands” the proposed Muslim ban by Trump, also a Christian, but the senator does not support it, saying there are millions of Muslims who are not murderous. Instead, Cruz supports stopping refugees from some predominantly Muslim countries from coming to the United States. Democratic politicians and others have condemned Republican candidates’ remarks on Islam, saying they foster further division and discrimination. 