"It's called promises made, promises kept".
The President also criticized Andrew Gillum, the Democratic Party's candidate for the post of Florida Governor, for seeking to abolish the federal agency, US Immigration and Customs Enforcement, which he said was "full of patriots" who arrested 127,000 illegal immigrants a year ago.
It did not take long for the video to go viral, with many praising the former president.
Trump also said "nobody was worse to the press than Obama", after Obama spoke in defense of the First Amendment.
The former and current presidents are barnstorming the country ahead of the elections, in which Democrats hope to win control of the House of Representatives, gain Senate seats and pick up governor's mansions and state legislatures across the country ahead of the 2020 redistricting process.
Trump announced earlier this week that he would send thousands of troops to the border to beef up national defences at the border.
Trump received the type of jobs report that any president would envy heading into the final days before the midterm elections. You know, it's like, I enjoy that.
The FBI said on Friday it had recovered a suspicious package addressed to California billionaire Tom Steyer, a Democrat known for his ads calling for Trump's impeachment.
Meanwhile, campaign ads are sending conflicting messages.
Back in Montana on Saturday afternoon, he slammed Democratic Sen.
In some of his sharpest criticism of Trump yet, the former President cast his successor as a compulsive liar with an authoritarian streak.
His evidence: Davids held an apolitical fellowship at the Department of Transportation granted under Obama and which extended into the Trump administration.
Trump's campaign committee also released a television ad on Friday focused on immigration.
The committee is the election arm of House Republicans, who have backed Trump's moves to bolster the coal industry by rolling back environmental regulations.
Trump, who has placed immigration at the heart of his party's election effort, has persistently attacked the caravan of Central American migrants, denouncing it as a potential 'invasion'. "I do not want our borders overrun".
Knight, the former coach of the Indiana Hoosiers, embraced Trump's 2016 presidential campaign, often appearing with the future president at rallies in the state.
Information for this article was contributed by Ken Thomas and Ellis Rua of The Associated Press; and by Sahil Kapur of Bloomberg News.