The world's largest technology companies and 17 US states support a legal challenge to President Donald Trump's Muslim ban, but several right-wing groups also stand firm with the president.

Among them are groups that brought legal challenges demanding President Barack Obama prove his US citizenship known as "birthers," and others that lobby against gun-free zones in schools, and fight court battles to allow more money in American politics.

On Tuesday (7 February) during a contentious hearing before three judges in a San Francisco court of appeal, arguments were lobbed between attorneys for the President and two states. Washington and Minnesota are both suing to overturn President Trump's executive order blocking people from seven Muslim majority countries from entering the US.

The case will decide if the courts have a right to temporarily block Trump's order before heading to trial.

The government on Tuesday asked the appeals court to restore the order, arguing the president alone has the power to decide who can enter or stay in the United States.

The right-wing groups – including the US Justice Foundation, Citizens United, English First, Gun Owners of America, the Conservative Legal Defense and Education Fund, US Border Control Foundation, and Policy Analysis Center – drew up legal arguments supporting this line of attack on Monday (6 February).

It's the opposite tack to companies like including Apple, Facebook, Google, and Intel, and civil rights groups, including the American Civil Liberties Union, and 15 US states that sayTrump's executive order harms American business and the states.

The right-wing groups cite the fact that "the processing of refugees by DHS officers takes place in foreign refugee camps," where it is difficult to verify claims and obtain documents, justify Trump's proposals for increased vetting outlined in his executive order. "Flexibility in the law" around refugees, they say, may help victims of persecution but "also allows others to exploit the system."

Each group has been involved in other right-wing causes outside of immigration. Learn more about some of them below.

US Justice Foundation

The USJF is a group of "attorneys seeking to advance the conservative viewpoint" and in 2009 was part of legal action to force Barack Obama to produce his birth certificate. In 2001 its executive director Gary Kreep called for lifting a ban on the assassination of foreign leaders made in an executive order by President Gerald Ford in 1976. "The revival of an ability to defend our nation by assassination of rogue leaders is more than justified given the present threats of biological, chemical and nuclear violence against the United States by foreign states," wrote Kreep in a paper.

Citizens United

This right-wing Political Action Committee (PAC) seeks to "reassert the traditional American values of limited government, freedom of enterprise, strong families, and national sovereignty and security." Made a household name by the Citizens United v. Federal Election Commission case, which went to the US Supreme Court, the group led the charge in making political spending by corporations and unions a form of protected speech. Citizens United has also produced several documentaries that take on the United Nations, Hillary Clinton, and Barack Obama.

Gun Owners of America

Founded in 1975 the group supports gun rights and has over 1.5 million members. The group has often sharply criticised the large National Rifle Association of America for compromising on gun rights issues. It has lobbied against a bill that would eliminate gun-free school zones, efforts to expand background checks, and the outlawing of .50 calibre rifles or ammunition.