He also sought to favorably contrast the way he made his money with the way Hillary Clinton has earned a living in her career, and pitched himself as an underdog who has overcome obstacles time and again in his career.
“While I made my money as a very successful private business person following the law all the way, Hillary Clinton made her money as a corrupt public official,” said Trump, offering a variation on his repeated criticism that Clinton is "crooked."
Throughout his speech here, Trump cast himself as an underdog in business, weaving in and out of stories about his real estate career. He said his grasp of tax laws helped him stay afloat while others in his field fell flat in the 1990s.
“My understanding of the tax code gave me a tremendous advantage over those who didn’t have a clue about it,” said Trump.
Looking back, Trump said: “These tough times were when I performed my very best.”
Trump called the nation’s tax system “complex” and “unfair” and blamed it on the political class, not the Internal Revenue Service. He said he has had a "fiduciary responsibility" to “pay as little tax as legally possible." But the intense scrutiny has centered on Trump's personal taxes, not his business filings.
He also acknowledged that he has benefited from the laws, but added, “I’m working for you now, I’m not working for Trump.” Trump added that because he is someone who understands the tax laws so well, he is well-equipped to repair them.
The GOP nominee also opined on other issues. He said the country is growing more divided, with "race riots on our streets on a monthly basis."
"Somebody said don't call them race riots. But that's what they are," Trump said. He went on to mention the unrest in Charlotte, N.C., and Ferguson, Mo., where protests ensued after deadly police shootings of African Americans.
Trump's microphone malfunctioned a few times, and he quipped that the Commission on Presidential Debates must be controlling it — a reference to audio issues he complained about during last week's debate.
He called the commission "a joke" toward the end of his remarks.
Trump received loud cheers during his remarks. But there were protesters outside and at least one person inside his rally who yelled at him to pay his taxes.
At a rally later in the day in Loveland, Colo., Trump made a similar pitch to the one he made in Pueblo. At the later event, a protester entered the media area before being removed:
In his remarks, Trump tried to drive a wedge between supporters of Sen. Bernie Sanders (I-Vt.) and Clinton, saying Sanders should not have "made a deal with the devil," an apparent reference to his decision to endorse Clinton after losing to her in the Democratic primary.
This post has been updated.