For the sixth consecutive month, Republican midterm voters have told pollsters that immigration is the most important issue facing the United States.

Every year, the U.S. admits more than 1.5 million foreign nationals, with the vast majority deriving from family-based “chain migration,” whereby newly naturalized citizens can bring an unlimited number of foreign relatives to the country.

In 2016, the legal and illegal immigrant population reached a record high of 44 million. By 2023, the Center for Immigration Studies estimates that the legal and illegal immigrant population of the U.S. will make up nearly 15 percent of the entire U.S. population.

The latest Harvard/Harris Poll reveals that for the last half year, between March and August, GOP voters have said immigration is the most important issue in the country – not tax reform, healthcare, or even the economy.

In August, a majority of 53 percent of GOP voters said immigration was their biggest issue heading into the midterm elections. That’s up from the 46 percent of GOP voters who said the same last month.

That number is also up more than ten percentage points when compared to six months ago, in March, when 42 percent of GOP voters said immigration was the biggest issue. At the time, immigration still ranked as the number one issue to Republicans ahead of the midterms.

Likewise, for the past three months, immigration has been the biggest issue in the midterm elections for all American voters. In August, a plurality of 34 percent of voters said immigration was the most important issue facing the nation.

The poll is welcome news for President Trump — who won the 2016 presidential election on his commitment to reducing overall immigration to the U.S. by promising to build a border wall and cut the annual inflow of foreigners entering the country through a merit-based system.

Watch: Trump Refocuses Midterm Elections on Immigration, ‘Blue Wave Means Crime, Open Borders’https://t.co/cT1MggO196 — John Binder 👽 (@JxhnBinder) August 20, 2018

Trump’s “America First” immigration agenda has had widespread support for years now. A previous Harvard/Harris poll found that nearly two in three voters support Trump’s effort to reduce overall immigration to the country — the U.S. currently admits more than 1.5 million foreign nationals every year.

Ending the Catch and Release program, whereby illegal aliens are released into the interior of the country while they await immigration hearings, also has 3:1 support among voters, Breitbart News reported.

Most recently, the majority of white, black, and Hispanic Americans told pollsters they support stricter enforcement of U.S. immigration laws. The Harvard/Harris poll revealed that 77 percent of white voters, 53 percent of black voters, and 51 percent of Hispanic voters said they believe the U.S. needs to crack down on immigration laws.

The massive importation of low-skilled foreign nationals to the U.S. has translated to a cheap labor economy that has aided in keeping American mens’ wages stagnant for at least 44 years, as Breitbart News reported. Median earnings for American men working full-time were actually lower in 2016 than they were in 2007.

John Binder is a reporter for Breitbart News. Follow him on Twitter at @JxhnBinder.