Politicians, lawyers, and activists in Washington are engaged in a heated fight over just nine words that Donald Trump wants added to the 2020 census, which could have major implications for political representation and the distribution of federal funds across the country.

“Is this person a citizen of the United States”, the question, which has not been included in the decennial census for decades, would ask.

The issue has already seen its day in the Supreme Court, but the president has continued to push forward to try to include the question in the questionnaire that will be sent to every household in America, even after the stated deadline to begin printing the documents.

Mr Trump had been expected to flat out defy the Supreme Court through an executive order — but grudgingly conceded defeat in a speech at the White House.

Here’s what you need to know:

The way we were: 100 years of the British census Show all 7 1 /7 The way we were: 100 years of the British census The way we were: 100 years of the British census 1911: Extreme poverty persists for the likes of this young family in London's Chinatown Getty Images The way we were: 100 years of the British census 1921: The fireplace remained the centre of the home Getty Images The way we were: 100 years of the British census 1921: This Woking family were reduced to living in a pig shed Getty Images The way we were: 100 years of the British census 1931: A London family gathers around the wireless to hear General Election results Getty Images The way we were: 100 years of the British census 1951: A teenager applies lipstick in Birmingham. War interrupted the census takers in 1941 and after two decades much had changed Getty Images The way we were: 100 years of the British census 1961: A Hackney couple with their young family. Population had grown by five per cent over the previous ten years Getty Images The way we were: 100 years of the British census 2011: The next census is due to take place later this month. How typical are households like that of Gabriel Prokofiev and Makila Nsika? Dominick Tyler

What is the census and what does it impact?

The census is an extensive count of the population in the country, and is conducted every 10 years in accordance with the US constitution. The questionnaire is sent to every household, and asks a set of questions about everyone living there on a particular date, including their sex, age, and other details.

The count has a massive impact on the way the country works, touching upon everything from federal funding allocations for $900bn to political representation.

What appears to be of special interest in this case is political representation, with the census having a major impact on the allocation of electoral college votes to states, as well as having an impact on the number of House seats any particular state gets.

What is the citizenship question, and when was it last asked?

The Trump administration has asked for the following question to be included in the 2020 census: “Is this person a citizen of the United States.”

Respondents would then be able to choose between five options to answer. They could say they were born in the US, were born in a US territory, were naturalised, were born to US citizens abroad, or that they are not a citizen.

The last time that citizenship status was asked on the census was in 1950, when the census asked this question and follow-up: “If foreign born — Is he naturalised.”

Technically, if Mr Trump had got his way on the citizenship question, then it would have been the first time that citizenship status had ever been asked about directly on a US census.

Nancy Pelosi reacts to Supreme Court blocking citizenship question from entering 2020 Census

Nancy Pelosi reacts to Supreme Court blocking citizenship question from entering 2020 Census

How would it impact the tally?

Critics of the question say that it could depress the count of immigrants in the country, and ultimately make the count less accurate.

The American Civil Liberties Union is among those who have made the argument, and have said that it would divert federal money and political power from states and cities where large numbers of non-citizens live, and push that power into more rural areas of the country.

“The impacts will be severe and will last at least a decade. It’s going to cause a huge undercount, and that means that those communities will suffer,” Kelly Percival, counsel with New York University’s Brennan Centre for Justice’s Democracy programme, told The Independent.

She added: “It’s about political representation, but it’s also used to appropriate about $900bn in federal funding every year. We’re talking things like food, healthcare, education, all these things that Congress is going to allocate money for, they go to these communities based on who has been counted in these communities. If you have a bunch of people not counted, then they’re going to lose money for essential services.”

One government estimate found that around 6.5m fewer people would be counted in the census with the question. And, courts have found that Arizona, Florida, California, Florida, Illinois, New York, and Texas could lose seats in the House as a result.

Supreme Court blocks Trump administration from adding citizenship question to 2020 census

What has been the Trump administration’s rationale for the question?

Originally, the commerce department said it had added the question on request from the justice department, which itself said that the information was necessary to enforce the Voting Rights Act.

That law is intended to protect minority voters from discrimination, and the government says it needs an accurate count of eligible voters in order to do that.

But the US Supreme Court ruled last month that the commerce department had not supplied sufficient evidence for the inclusion of the question, and calling the inclusion “contrived”.

How does the US currently count voter eligible citizens?

Currently, there is a questionnaire sent out to a much more limited number of people, asking about citizenship status.

Why did the Supreme Court side against Mr Trump’s administration?

The decision was handed down 5-4, with chief justice John Roberts siding with the three minority liberal justices on the bench.

The decision was something of a surprise, after observers of the court at the time of oral arguments reported that they believed that the court would ultimately side with the government and allow the question. Instead, they shot it down, but left the door open for the government to provide a new reasoning.

AOC comments on the census citizenship question: 'I want to know about racism and the very disturbing history that we're seeing here'

AOC comments on the census citizenship question: ‘I want to know about racism and the very disturbing history that we’re seeing here’

What happened in between?

It’s not completely clear what impacted the thinking of the justices, but between oral arguments and the decision, information on hard drives from the late Republican strategist Thomas B Hofeller was introduced into the record.

Those documents revealed that Hofeller had written a report in 2015 that suggested adding a citizenship question to the census would give Republicans an edge when redrawing legislative districts, and a disadvantage to minority communities and Democrats. Hofeller’s document also revealed that he wrote a portion of the draft argument the Justice Department put forward to argue for the question.

What has happened since?

In early July, the US Commerce Department announced that it would begin printing the census.

Just a day later, Mr Trump tweeted that they would proceed with their efforts to add the question, creating havoc in the courts where Justice Department lawyers later claimed they were not aware of the president’s position on the issue.

Those lawyers then made the unusual decision to step away from the case, forcing the US government to scramble to try and put new lawyers on the case. The courts have since said that the original lawyers cannot leave unless they provide an adequate explanation, and have blocked the government from appointing new legal counsel.