Daily SumUp

In one of his first acts as the 47th president of the United States, Donald Trump signed an executive order aimed at ending automatic citizenship rights for nearly anyone born on US territory - known as "birthright citizenship".

It's a policy change he's long promised - but implementing it won't be easy. It has faced legal challenges and has been taken by Trump to the US Supreme Court.

Trump's order seeks to deny citizenship to the children of people who are either in the US illegally or on temporary visas.

But it already has been blocked by courts in the early stages of what promises to be a long battle.

Most legal scholars say the president doesn't have the power to unilaterally change the law in this area, which is based on an amendment in the US Constitution.