HOUSTON (CBSDFW.COM/AP) – President Donald Trump says nobody helped him more to cut taxes and regulation than Texas Sen. Ted Cruz.

Trump said Monday at a political rally in Houston that Cruz has “become a really good friend of mine.”

Cruz is running for re-election in the midterms against Democratic Rep. Beto O’Rourke.

President Donald Trump at Houston rally (CBSDFW.COM)

Trump spoke before a massive crowd on behalf of his onetime rival for the 2016 Republican presidential nomination.

During the campaign, Trump would frequently deride his former foe as “Lyin’ Ted” but said in Texas that their relationship had come a long way.

Speaking before Trump took the stage, Cruz also made clear the conflict was behind them and that the two were working together.

His biggest applause came when he predicted that “in 2020 Donald Trump will be overwhelming re-elected.”

Sen. Ted Cruz at Houston rally (CBSDFW.COM)

CBS 11 political reporter Jack Fink spoke with President Trump briefly before his speech.  He talked about his relationship with Sen. Cruz, getting out the vote in Texas and the caravan of migrants heading to the U.S.

During the rally, President Trump also attacked O’Rourke, dubbing him a “stone-cold phony.”

With the midterms drawing near, Trump targeted a migrant caravan heading to the U.S. southern border. Trump called the caravan an “assault on our country” and said “Democrats had something to do with it.”

“We need a wall built fast,” Trump said.

Immigration politics have become a central part of Trump’s closing message as he seeks to energize Republican voters in the midterm elections. Trump has seized on the caravan of Central Americans as evidence that his immigration prescriptions are needed. Earlier Monday, he said the U.S. will begin “cutting off, or substantially reducing” aid to three Central American nations because of the caravan.

The president’s focus on immigration politics comes as he seeks to counter Democratic enthusiasm in November. But the approach offers both risks and rewards. He could energize Democratic foes as well as the Republicans he wants to rouse to the polls.

Monday’s event bore all the trappings of a Trump rally. An enthusiastic crowd packed into Houston’s Toyota Center, wearing red Make America Great Again hats and waving signs, including one with the president’s new catchphrase, “Jobs vs. Mobs.” Some did the wave as they waited for the event to start; others shouted “Trump, Trump, Trump!” and “Build the wall!”

Speaking before Trump took the stage, Cruz made clear that their conflict was behind them and that the two were working together. His biggest applause came when he predicted that “in 2020, Donald Trump will be overwhelming re-elected.”

A series of Texas elected officials were among the warmup speakers, as well as Trump’s daughter-in-law Lara Trump and son Eric Trump, who told the audience that “we are driving the Democrats absolutely nuts.”

Trump gleefully used his latest attack line against Democrats, saying, “Democrats produce mobs, Republicans produce mobs.” He declared Democrats would be a “big risk to the American family,” and went after some of his favorite targets, including Democratic House Minority Leader Nancy Pelosi, California Rep. Maxine Waters, New Jersey Sen. Cory Booker and Massachusetts Sen. Elizabeth Warren.

The president stressed tax cuts, the strong economy and hurricane response in the state. He repeated his pledge for a new middle-income tax cut of about 10 percent, though he offered few details on the plan. Trump said they would be “putting it in” next week, though Congress is not in session.

Trump also criticized so-called globalists, declaring, “You know what I am? I’m a nationalist.”

Trump’s Texas stop is part of a campaign blitz that is expected to last until Election Day.

Although political relationships tend to be fluid, Trump’s appearance for Cruz is notable, given that the two were bitter enemies during the 2016 primaries. After Trump insulted Cruz’s wife and father, and Cruz refused to endorse Trump at the Republican convention, it was far from clear that the two would ever put it all behind them.

But they started rebuilding in the closing days of the campaign and have worked together since Trump took the White House.

The White House views Cruz as a loyal vote for his agenda. Trump promised he would come to Texas after the Senate race grew closer than expected, with O’Rourke out-fundraising Cruz and drawing large and enthusiastic crowds around the state. Cruz, who is leading O’Rourke in the polls, said over the summer that he would welcome Trump’s support, though he has brushed off any suggestion he’d need Trump to win.

During the 2016 Republican primary, Trump assailed Cruz as a liar and “dishonest politician,” insulted his wife’s appearance and promoted unsubstantiated claims that Cruz’s father had links to President John F. Kennedy’s assassin, Lee Harvey Oswald.

Trump on Monday did not voice any second thoughts about labeling Cruz the son of a presidential killer, telling reporters, “I don’t regret anything.”

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)