Donald Trump has suggested he will end the centuries-long, amendment-protected practice of providing birthright citizenship in the United States by signing an executive order.

The only problem? He can’t.

The president said in a Tuesday interview that birthright citizenship “has to end,” repeatedly calling the practice “ridiculous” and suggesting he can put a halt to it through the signing of an executive order.

“It was always told to me that you needed the Constitutional amendment,” he said in a recent Axios interview, a portion of which was released Tuesday morning. “Guess what? You don’t.”

Birthright citizenship is an American tradition that was adopted into the US Constitution in 1868 through the ratification of the 14th Amendment.

That amendment states “all persons born or naturalized in the United States” are granted citizenship, including former slaves who had just been freed following the US Civil War.

The amendment was explicitly found to protect child immigrants born in the United States in the 1898 case US v Wong Kim Ark. At that time, the Supreme Court held that children born to foreigners permanently and legally residing in the country “becomes at the time of his birth a citizen of the United States, by virtue of the first clause of the Fourteenth Amendment of the Constitution.”

A later 1982 case Plyler v Doe also applied the 14th Amendment to immigrant children, holding that the denial of public school admission to undocumented immigrant children violates the amendment’s equal protection clause.

Mr Trump criticised the practice on Tuesday while discussing immigration, saying, “We’re the only country in the world where a person comes in and has a baby, and the baby is essentially a citizen of the United States for 85 years with all of those benefits”.

“It’s ridiculous. It’s ridiculous. And it has to end,” he continued. “You can definitely do it with an act of Congress. But now they’re saying I can do it just with an executive order.”

However, executive orders cannot amend — and must work within — the parameters of the US Constitution.

Trump says he plans to build 'tent cities' for people traveling with the caravan

Trump says he plans to build 'tent cities' for people travelling with the caravan

Regardless, Mr Trump appeared to court controversy by suggesting he could demand the end to birthright citizenship without the arduous process of amending the constitution; a move that would typically require two-thirds support from both Houses and three-fourths support from all 50 states.

The president could otherwise urge for a Constitutional Convention, which would require the support of two-thirds of the legislatures, and any amendments made during the convention would still need three-fourths support of the states.

It seems unlikely the vast majority of US lawmakers would suddenly seek to ratify birthright citizenship out of the constitution, however, it is among the extremely limited ways it may be legally possible.

The Independent goes on a ride-along with US Border Patrol Show all 15 1 /15 The Independent goes on a ride-along with US Border Patrol The Independent goes on a ride-along with US Border Patrol Texas and Mexico are connected by entry points like these. US Border Patrol in Laredo, Texas conducts daily patrols throughout the Rio Grande, snaking between the US and Mexico, where it searches for migrants and drug traffickers. The legal entry point to Mexico can be seen above the riverines frequently used by cartels to funnel narcotics into the US. Chris Riotta The Independent goes on a ride-along with US Border Patrol US Customs and Border Protection oversees its side of the entry point. US Customs and Border Protection officers oversee the processing of nearly two million trucks and three million pedestrians annually at the Laredo sector, which also processes the majority of trade between the US and Mexico. Chris Riotta The Independent goes on a ride-along with US Border Patrol The Rio Grande snakes between Mexico and the United States. The US and Mexico have bordering coastlines in Laredo Texas, where the Rio Grande's occasionally rough currents splash onto both nations' shores. For migrants attempting to enter into either country, the swim is much more dangerous than it appears. Chris Riotta The Independent goes on a ride-along with US Border Patrol Drug traffickers and migrants use "highways" to cross the border. US Border Patrol agents call worn pathways like these "highways," as they are frequently used by drug traffickers and migrants entering into the US. Chris Riotta The Independent goes on a ride-along with US Border Patrol The journey is still far from over. If they're able to make it onto land, many obstacles still remain for migrants and drug traffickers. US Border Patrol agents are equipped with high-tech security, K-9 units and aerial camera footage surveilling 40 miles of borderlands. Chris Riotta The Independent goes on a ride-along with US Border Patrol Border Patrol uses classic methods and high-tech to surveil the border. A control room at the Laredo sector headquarters is fully-manned 24/7 with a team of local employees who alert agents on the ground of border crossings in real-time. Their cameras live-stream 40 miles of the 170 mile territory the sector covers. Chris Riotta The Independent goes on a ride-along with US Border Patrol The US provides trusted traveler programs on both its southern and northern borders. Officers lead the way to Sentri offices, which runs a trusted traveller program from US and Mexican local residents who regularly cross the border for work or leisure purposes. Chris Riotta The Independent goes on a ride-along with US Border Patrol The pathway to freedom. Once travellers are processed, they walk up this ramp towards the US. Many Mexicans cross the border each day with collapsable shopping carts to buy goods while visiting the country. Chris Riotta The Independent goes on a ride-along with US Border Patrol But first, the wait. A dog waits for their owner to go through processing with US Customs and Border Patrol. On a good day, processing can take under an hour. On a bad day, well, there's just no telling how long one might be stuck inside the Laredo sector field offices. Chris Riotta The Independent goes on a ride-along with US Border Patrol The first lady of CBP. Inside the Laredo field offices, US Border Patrol agents keep a framed photo of Christine Davis, the first female agent to join the federal agency in 1975. Chris Riotta The Independent goes on a ride-along with US Border Patrol "The hall of fame." US Border Patrol also honors those who have served in the agency for over thirty years. Chris Riotta The Independent goes on a ride-along with US Border Patrol Officers inspect a vehicle in secondary processing. Outside, officers are conducting secondary inspection on a vehicle that's been pulled aside for further investigating. Chris Riotta The Independent goes on a ride-along with US Border Patrol The waiting room for detained migrants. A US Customs and Border Protection officer shows the inside of a holding room where people requiring further questioning go through secondary processing. Chris Riotta The Independent goes on a ride-along with US Border Patrol A man and his daughter go through processing. US Customs and Border Protection also regularly provides humanitarian visas and other temporary permissions for people with valid reasons seeking entry to the US. Here, a father and his daughter await to see whether they will be provided one of those visas. Chris Riotta The Independent goes on a ride-along with US Border Patrol Laredo processes over three million pedestrians annually. Thousands of legal asylum seekers, migrants and refugees seek entry to the US through the southern border annually, where they go through processing at offices like this after arriving at a legal port of entry. For many, the trip can take days, if not weeks or even months. Chris Riotta

If the president were to sign an executive order denying the practice, either forth outright for all non-citizens or specifically for children born to parents lacking permanent legal status, it would almost immediately be considered illegal by numerous US courts.

Once an executive order is deemed illegal, it is overturned — which has happened on numerous occasions. In fact, earlier this year a US District judge ruled Mr Trump exceeded his authority by signing an executive order that made it easier to fire federal employees, striking down key components of the mandate.

Previous versions of his executive orders banning travel to the US from several Muslim-majority nations was also blocked by courts across the country.

Support free-thinking journalism and attend Independent events

But with seven days until the first national election since Mr Trump was elected, the president appears to be rallying his base around the issues that helped him secure the Oval Office in 2016.

The president has repeatedly pointed to a migrant caravan nearly 1,000 miles away in southern Mexico as a major cause for concern ahead of the crucial midterm elections — and a reason to vote Republican, suggesting the Democrats want “open borders” and to allow in unlimited immigrants across the US-Mexico border.