President Trump is pushing the benefits of the GOP tax overhaul at a roundtable with business leaders in Cleveland Saturday, as Republicans attempt to use the law to catapult their way to victory in the midterms this fall. But staying on-message may prove a challenge for the White House.

"Remember, you have to win the great state of Ohio. And did we win the great state of Ohio," Trump said to open up the event, referencing his election win.

Mr. Trump didn't start out talking about tax reform — he spoke of what he described as unfair trade policies, and unacceptable illegal immigration. The president said it may be necessary to "close the country" until a border wall is built.

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"Our borders are and our laws are a mess," the president said. Our immigration laws are a disgrace. And Mexico has very some of the toughest immigration laws in the world. You can't just go into Mexico — but they allow these people to come up through Mexico and into our country." The president described his frustration with how Mexico handled a "caravan" of migrants from Central American. Mr. Trump said Democrats "want open borders."

"If you don't have borders, you don't have a country," he said.

But the president did touch on the tax law — the "biggest" in U.S. history, he said, a claim he has continued to make, despite it being proven incorrect. Mr. Trump described how he wanted to call the bill the tax "cut, cut, cut, cut" act, but other Republicans found it too "hokey." He invited guests on stage with him to share how the tax bill has increased their paychecks. Sherry Sheely, the COO of her family's furniture retail and appliance store, said the tax bill enabled her business to give unexpected $500 bonuses to their staff.

"We had several employees who got so emotional, they cried," she said.

Young father Chris Jaramillo said he and his wife were able to start a college savings account for their 1-year-old son with the $500 he received from a bonus from his company, and place him in a better daycare with the $125 more he is seeing in his paychecks because of the tax law.

Rep. Jim Renacci, the Republican running in an attempt to take Ohio Democrat Sen. Sherrod Brown's seat in November, said at the event that the tax cuts are "working."

The president said Renacci is looking good ahead of the election — "Go out and help Jim, we'll get it done," Mr. Trump said.

Mr. Trump's visit to Cleveland is a part of the broader GOP attempt to use December's tax reform to bolster their chances in what will be a tough midterm election cycle. But the bill's popularity isn't certain. A March 2018 Gallup poll found the bill had been gaining in popularity, but still had higher disapproval -- 48 percent -- than approval, at 39 percent.

Staying on message, however, can sometimes be a challenge for the White House. On Friday, Mr. Trump was in a talkative mood en route to Dallas, where he addressed the National Rifle Association. He stopped to talk to reporters at the White House, Joint Base Andrews in Maryland and on Air Force One. As the White House looked to stay on message about pressing issues securing the nomination of Gina Haspel, nominated to run the CIA, and a positive jobs report, Mr. Trump offered his opinions on his lawyer, Rudy Giuliani, as well as Stormy Daniels and the Russia investigation.

Giuliani told Fox News' Sean Hannity Mr. Trump "reimbursed" his longtime attorney Michael Cohen for Cohen's $130,000 payment to Daniels, whose real name is Stephanie Clifford, ahead of the 2016 election. Mr. Trump seemed to confirm that repayment in tweets Thursday, before claiming on Friday Giuliani didn't know the full situation and will "get his facts straight."

Mr. Trump's appearance in Cleveland also comes after the president announced Friday a date and location have been set for his meeting with North Korea's Kim Jong Un, although Mr. Trump didn't share the details.