A spokesman for Donald Trump’s campaign vehemently denied a report that two staffers got into a physical altercation with an official at Arlington National Cemetery on Monday, despite the cemetery confirming there was an incident — and a report was filed. NPR reported, citing a source with knowledge of the incident, that two campaign staffers got into a verbal and physical altercation with an official who tried to prevent campaign staffers from entering a specific section of the cemetery. Trump was there as part of a wreath-laying ceremony. Campaign spokesman Steven Cheung, known for his often…