U.S. immigrant deportations have fallen to the lowest level since 2007, a recent Department of Homeland Security paper has revealed. The Obama administration deported a total of 333,341 illegal migrants in 2015, a decline of around 20 percent from the previous year.

A Key Issue

Immigration was a key issue in Donald Trump's successful election campaign. Famously, Trump proclaimed that he will build a wall to prevent illegal Mexican immigrants from entering the U.S.Although Trump has yet to begin erecting a wall, immigration has been a staple issue in political debates across Europe.

In the U.K, Nigel Farage, former leader of UKIP, used immigration as a political pawn to encourage citizens to vote for Brexit. Similarly, the Five Star Movement in Italy has enjoyed success due to their staunch anti-immigration rhetoric.

In the U.S., the decline in deportations has occurred across both non-criminal and criminal immigrants. Last year, 193,000 non-criminal immigrants were deported from the U.S. That figure is down significantly from 247,000 in 2014. 140,000 criminal immigrants were deported in 2015- the number is down from 168,000 deported immigrants in the previous year.

It is only the third time that illegal immigrant deportations have declined since 1981 in the U.S.The report suggests several reasons why the number of deportations has decreased over the past year.

One of the causes of the decline in deportation is due to the number of arrests at the U.S.-Mexico border decreasing, a figure that has been on the decline for a number of years.

Furthermore, there has been an overall decrease in the number of immigrants, legal or illegal, attempting to enter the U.S over the past few years.

A PEW Research Centre study found that, between 2009 and 2014, the number of Mexicans returning back to Mexico was significantly larger than the number of immigrants arriving in the U.S.

In the past year, the Obama administration changed their deportation policy to focus on deporting criminal illegal immigrants. In total, around 2.8 million immigrants have been deported by the Obama administration during his presidency.

In contrast, the Bush administration deported around 2 million illegal immigrants between 2001 and 2008. During his election campaign, president-elect Donald Trump promised to deport a total of three million immigrants during his term in office.