LAKEWOOD — The head of the union representing postal carriers, accompanied by an energized Gov. John Hickenlooper, on Monday denounced remarks made by GOP presidential candidate Donald Trump over the weekend that raised questions about the integrity of Colorado’s mail-ballot election.

Doug Jaynes, the president of the Colorado State Association of Letter Carriers, called Trump’s remarks during a Saturday rally in Golden in which the candidate talked about mailed-in ballots being potentially thrown away an “insult” to his profession.

“It’s so important that people don’t get concerned that their ballots aren’t safe,” Jaynes told a small gathering of Hillary Clinton supporters at a Democratic campaign office in Lakewood.

Hickenlooper, a Democrat, touted the integrity of the U.S. Postal Service and asked in a scoffing tone how postal carriers would even know which ballots to discard if they were engaged in such activity.

“What do they have — X-ray eyes?” he asked, to laughter in the room.

He called Trump’s remarks “nonsense” and “beyond the pale.”

Trump told a crowd at the Jefferson County Fairgrounds Saturday that he had “real problems” with Colorado’s mail-ballot election. He did so again at a speech in Greeley on Sunday. This year is the first time the state has conducted a presidential election using mail-in ballots, though it has done so for non-presidential elections numerous times.

“Like people say, ‘Oh here’s a ballot. Here’s another ballot, throw it away. Oh, here’s one I like. We’ll keep that one,’” Trump said Saturday in describing the possibilities for voter disenfranchisement in Colorado.

It wasn’t clear exactly who Trump was referring to with the term “people,” though the postal service and the various county clerks’ offices around the state would be the ones with access to sealed ballots mailed in by voters. Asked numerous times to identify who Trump thought might illegally discard ballots this election season, his campaign spokeswoman in Colorado didn’t provide an answer.

Hickenlooper on Monday noted that most county clerks in the state are Republican and Colorado’s secretary of state, Wayne Williams, is a Republican.

State elections officials have pushed back on Trump’s more general assertions about the potential for voter fraud this year. Pam Anderson, executive director of the Colorado County Clerks Association, said in her eight years as Jefferson County clerk she never once received a complaint from a voter about a ballot having been tossed by her staff.

“I would certainly be interested in any evidence to that assertion,” she said.

Anderson said voters can easily check the status of their ballot online at govotecolorado.com, immediately learning whether a ballot they mailed was received at their county clerk’s office.

“I’m not sure what the motivation is here, but I disagree with it wholeheartedly,” she said of Trump’s comments.