President Donald Trump on Monday doubled down on his call for undocumented immigrants who enter the United States illegally to be sent back to their native countries without any due process before an American judge.

Trump first made the claim in a Sunday tweet following his Saturday contention during remarks before the Nevada Republican Party that Democrats want to open the southern border so the violent MS-13 gang can spread “all over our country.”

The president in recent days has ratcheted up his immigration rhetoric in a clear sign he wants to make it part of his and the GOP’s midterm election message. On Friday, a White House official did not dispute that, but noted the party has other items to tout like the economy and its tax cut bill.

[House GOP ‘Uphill Fight’ on Immigration About More Than Trump]

But during remarks Saturday in Las Vegas, the president said he intends “to use this issue — and I like the issue for [the] election, too.”

Watch: Activists Play Audio of Separated Children in Front of White House

He continued doing just that on Monday morning, firing off a tweet during his morning “executive time” in the White House residence.

Hiring “many thousands” of additional immigration judges to meet a growing demand along the U.S.-Mexico border then having adult migrants “going through a long and complicated legal process, is not the way to go – will always be disfunctional.” (The president misspelled dysfunctional in his tweet.)

Trump says migrants “must simply be stopped at the Border and told they cannot come into the U.S. illegally.” As for children who are brought to the border by their parents or other adults, the president said they should be “brought back to their country.”

Hiring manythousands of judges, and going through a long and complicated legal process, is not the way to go – will always be disfunctional. People must simply be stopped at the Border and told they cannot come into the U.S. illegally. Children brought back to their country……

— Donald J. Trump (@realDonaldTrump) June 25, 2018

….If this is done, illegal immigration will be stopped in it’s tracks – and at very little, by comparison, cost. This is the only real answer – and we must continue to BUILD THE WALL!

— Donald J. Trump (@realDonaldTrump) June 25, 2018

In another tweet and without supporting data, the president said if his preferred process is adopted “illegal immigration will be stopped in it’s tracks – and at very little, by comparison, cost.”

Congress established the existing immigration process, meaning legislation is needed to change it. Trump does not possess the executive powers to do so on his own. And last week, three of the four congressional leaders said it is unlikely Congress can agree on any immigration bill, making it unlikely the existing process will change.

The Monday morning tweets came two days after Trump declared Republicans’ “issue is strong borders, no crime.” On the other hand, “their issue is open borders, get MS-13 all over our country,” he said of Democrats in a midterm campaign-trail preview.

“We need people to come in, but they have to be people that love this country, can love our country, and can really help us to make America great again,” he said Saturday. And using the same kind of plain-spoken rhetoric he used in his 2016 presidential bid, the president vowed to throw MS-13 members in “paddy wagons” and get them “the hell out of our country.”

[Analysis: Donald Trump’s No Good, Very Bad Week]

But Sen. Angus King, a Maine independent who caucuses with Democrats, said Sunday on NBC’s “Meet the Press” that “people coming to claim asylum are not illegal immigrants.”

“Under the law, they have a right to establish their claim of asylum, that they’re in a legitimate fear for their life, that they’re fleeing persecution in their home country,” King said. “And that applies, by the way, to people coming from other parts of the world. But you have that right.”

Both King and GOP Sen. James Lankford of Oklahoma on Sunday said a big problem is a lack of immigration judges to process cases fast enough.

“There’s a bureaucratic backlog that can take a year or two in order to get your claim adjudicated,” King said. “The question then is, what do you do with these people in the interim? And the administration made the terrible choice of separating children from their parents. They didn’t have to do that. That wasn’t required by the law.”

The House could vote this week on a compromise GOP immigration overhaul measure that would address the child separation issue. But lacking conservative and Democratic support, it is expected to fail as a conservative alternative did late last week.