But documents obtained by The Huffington Post show that the candidate has also repeatedly fought to lower the amount he pays in state and local taxes, in some cases telling authorities that his properties are worth tens of millions of dollars less than he’s claimed in his federal election filings.

It’s a strategy that Trump has used across the country, and it can cost local communities hundreds of thousands in lost revenue they’d otherwise spend on schools, fire departments and other services. Trump’s tax reduction tactics are all the more jarring as his surrogates cite the enormous amount of state and local taxes he pays amid revelations that he used a massive write-off to avoid paying federal income taxes.

Steve Marcus/Reuters A view of the Trump International Hotel & Tower Las Vegas during its official opening on April 11, 2008. If Trump has underestimated the hotel's value to pay lower taxes, other taxpayers are "either going to have to pay higher taxes or put up with crummy services because he's not paying his fair share,” said law professor Richard Painter.

The wildly fluctuating reported value of the Trump International Hotel Las Vegas is a prime example of Trump’s approach. In July 2015, Trump convinced a Nevada tax board to reduce the taxable value of the hotel, which had initially been assessed at $176 million, to just $25 million. That much lower valuation would have cut Trump’s tax bill by millions of dollars in the 2015-16 tax year, and could continue to do so, if he’s paying the standard Clark County property tax rate.

Yet just six days after the tax board’s decision, which was obtained by HuffPost, Trump said the same property was worth over $50 million in a personal financial disclosure he filed with the Federal Election Commission. He repeated that value in an updated disclosure on May 16, 2016. (Candidates are only required to report the value of their assets in broad ranges, with the highest category being simply “over $50 million.”) Valuing his Las Vegas hotel at a higher amount made Trump’s net worth appear higher.

Both valuations can’t be true, said Richard Painter, a University of Minnesota law professor who was the chief ethics lawyer under President George W. Bush. “Either he’s not telling the truth to the board of equalization, or he’s not telling the truth about his assets on the [financial disclosure] and making himself look richer than he is,” he said.

Painter, who has endorsed Democratic presidential nominee Hillary Clinton, said that if Trump is lowballing the value of his building to pay lower taxes, he is effectively “cheating the other taxpayers of Nevada. They’re either going to have to pay higher taxes or put up with crummy services because he’s not paying his fair share.”

ROBYN BECK/AFP/Getty Images GOP presidential nominee Donald Trump went so far as to make a local library in East Fishkill, New York, issue him a $306 tax refund.

It’s a fairly common tactic for real estate developers to argue that a building is worth less than the local government claims in order to reduce their property taxes. However, Trump’s aggressive tax tactics are not always consistent with his personal financial disclosures, nor with his campaign’s insistence that the state and local taxes his company pays offset the massive federal income tax deduction he has apparently claimed.

Dan Lesser, a hotel valuation expert and the president of LW Hospitality Advisors, told HuffPost that valuation is never a straightforward process. Each appraiser uses his or her own assumptions about what something is worth, so it’s entirely possible to come up with different valuations within a “range of reasonableness.” The accuracy of a particular valuation is “in the eye of the beholder,” he explained. Without speaking directly to a specific property or valuation, Lesser said that if he valued a building and it went on to sell at an amount within 10 percent of his estimate, he’d consider his job well done.

For Trump’s Las Vegas hotel, a county tax assessor found that the taxable value of the land, building and personal property (including furniture) was just over $176 million for tax years 2014-2016. That finding was appealed in a January 2015 petition signed by Eric Trump, who is a vice president of Trump Ruffin I LLC, the company that owns the towers. In the appeal, he asked that the full value of the building be listed at $20 million ― which was even lower than the $25 million valuation by an appraiser the company had hired.

The Clark County tax board didn’t agree with that $20 million valuation, but did dramatically reduce its initial assessment, putting the hotel’s taxable value at a little over $48 million. Despite what seemed to be a favorable ruling, Trump Ruffin I LLC appealed again the next month, asking the state tax board to overrule the county and drop the property’s value all the way down to $20 million.

There was a hearing before the state tax board in May, and in July, the board agreed to lower the property’s valuation to $25 million, the figure the company’s own assessor had suggested.

If Trump’s company paid the standard property tax rate for the area, reducing the hotel’s taxable value from $176 million to $25 million saved it $4.4 million in property taxes in 2015-16 and could continue to do so.

Spokespeople for the Trump campaign and Trump Hotels did not respond to a request for comment from HuffPost.

Mike Segar/Reuters Is the Trump National Golf Club Westchester worth more than $50 million, or just $1.4 million? If you're Donald Trump, it seems to depend on the context.

Trump also fought to lower the assessment for his Briarcliff Manor, New York golf course from $13.5 million to just $1.4 million, the Westchester Journal News reported in September 2015. Yet in his 2015 and 2016 personal financial disclosures, Trump maintained that the golf course, which sits on 140 acres and has a 75,000-square-foot clubhouse, was worth more than $50 million.

Trump followed an almost identical routine for his golf course outside Charlotte, North Carolina. The Washington Post reported that after Trump bought the course for $6 million in 2013, invested $10 million in renovations and saw real estate values rise in the area, the course’s value dropped from $22.7 million to $9.6 million on the tax rolls of rural Iredell County. Since the purchase price and renovations alone cost $16 million and the Charlotte area is experiencing a real estate boom, that new valuation seems low. (In this case, Trump’s personal financial disclosure filings in 2015 and 2016 list the property’s value between $5 million and $25 million, a range that accommodates both the higher and lower assessed values of the property.)

Those valuation acrobatics in North Carolina saved Trump somewhere between $200,000 and $300,000 in total taxes and $167,000 in county taxes, the Charlotte Observer reported ― money that cuts directly into what the county has to spend on basic services like schools and roads.

Trump also fought the town of East Fishkill, New York, to retroactively lower the value of his Trump National Hudson Valley golf course from $6 million to $4.6 million for the 2015 tax year. The town settled the case in April 2016, agreeing to reduce the value to Trump’s proposed $4.6 million. Meanwhile, Trump’s 2015 disclosure to the FEC said the property was worth somewhere between $5 million and $25 million.

As part of the settlement, the town, county and local school district had to pay for an audit to determine if Trump’s company had paid any excess taxes in the previous year based on the new, lower, value. In the end, Trump managed to wring out refunds from the local governments: $31,367.06 from the Wappingers Central School District, $5,045.38 from Dutchess County, $4,141.25 from the town of East Fishkill, $1,066.06 from the East Fishkill Fire Department, and $306.99 from the public library.

A self-proclaimed billionaire lawyering up to get a penny shy of $307 back from a local library may seem inane and cruel. But to Trump, that’s business. As he told George Stephanopoulos in an interview on “Good Morning America” in May, “I fight very hard to pay as little tax as possible.”

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.