Former Denver Mayor Benjamin Stapleton was born the same year Ulysses S. Grant took the presidential oath of office.

Colorado treasurer and gubernatorial hopeful Walker Stapleton, Benjamin’s great-grandson, was born the same year Gerald Ford became the nation’s 38th president.

The sweep of time between both men exceeds a century, and neither strode the earth when the other did. But Benjamin Stapleton’s notorious role as a member of the Ku Klux Klan, while serving five terms as mayor of the Mile High City in the first half of the 20th century, lurks just below the surface of this year’s race for governor and presents pitfalls for the both Stapleton and his Democratic opponent, Jared Polis.

Last month, the New York Times ran a story titled “Family History Haunts GOP Candidate for Governor in Colorado,” while other news outlets have raised the issue of ancestral roots with Stapleton, who in past political campaigns has lauded his great-grandfather for helping bring the former Stapleton Airport and Red Rocks Amphitheater to Colorado.

Several seasoned election watchers told The Denver Post last week that voters are discerning enough to recognize that the younger Stapleton is not his great-grandfather and grew up in a different time in the state’s history. Still, the dark chapter in his family’s past is an issue that the Republican brushes aside at his own peril, they said.

“You can’t just ignore it,” said Eric Sondermann, a political analyst who has long kept an eye on state politics. “In this era of independent expenditures, it’s going to continue to come up.”

By independent expenditures, Sondermann is referring to the millions of dollars that interest groups not affiliated with political candidates have pumped into Colorado elections in recent years and will undoubtedly do again in 2018. Whether a third-party group decides to run an ad attempting to link Stapleton to his great-grandfather’s racist leanings, the candidate needs to be prepared — even proactive — about blunting any such attack, he said.

“He should make a statement about it,” Sondermann said. “I would do it one time for all to see, for all to hear.”

Pollster and political analyst Floyd Ciruli said Stapleton need not shine a light on the issue unsolicited but should have a response ready to go if the topic comes up.

“He needs to be ready to deal with this,” Ciruli said. “He needs a stock answer if it comes up again.”

Stapleton, when asked for his reaction to those who might use the legacy of his great-grandfather against him, gave the Post a short statement.

“All reasonable people understand my great-grandfather died in 1950, about 25 years before I was even born,” Stapleton said. “I am focusing on the future.”

A spokeswoman for Polis, who has been a Boulder congressman for the better part of a decade, declined to comment.

Stapleton wouldn’t be the first politician to have a controversial or embarrassing figure in his lineage. President Jimmy Carter had to deal with brother Billy, who was investigated for his close ties to Libya and did a stint in rehab for alcohol abuse in 1979. President Bill Clinton’s half-brother Roger was code-named Headache by the Secret Service for his sometimes erratic behavior.

In the entertainment world, actor Ben Affleck made headlines three years ago when he convinced the PBS show “Finding Your Roots” to excise from the broadcast the part of his ancestral story that included a slave-owning great-great-great-grandfather from Georgia. He said he was embarrassed by the revelation and “the very thought left a bad taste in my mouth.”

Stapleton hasn’t publicly denounced his great-grandfather’s involvement in the KKK, which Robert “Bob” Goldberg, a professor of history at the University of Utah and author of the book “Hooded Empire: The Ku Klux Klan in Colorado,” said was more pervasive than him simply being a mayor who happened to be in the Klan.

“This was a mayoral administration which was infiltrated by Klansmen,” Goldberg said. “The Klan was very influential in Colorado.”

Stapleton’s police chief was a Klansman, as were ranking members of his administration. At its peak, about 35,000 joined the KKK in Colorado, about half of them in Denver. Goldberg characterized the group as not just a social movement in 1920s Colorado, but a “political machine and an economic machine,” too.

Unfortunately for Stapleton, a movement underway in Denver that calls for the removal of Ben Stapleton’s name from all public spaces, including the burgeoning neighborhood on the east side of city that bears his name, threatens to continue breathing energy into the issue as the campaign for governor swings into full gear.

As embarrassing as the association may be, former state Republican chair Dick Wadhams said Stapleton has nothing to apologize for, citing the age-old adage that the sins of the father should not be visited upon the son. Voters understand that, he said.

“Fair minded people will not hold a candidate responsible for their great-grandfather,” he said.

But Wadhams acknowledged that there is no way to control outside interests that might try to exploit the issue in an advertisement or political mailing. Though he warned that such an effort, especially if launched by an independent group sympathetic to Polis, would likely backfire in the same way a pro-Cary Kennedy attack ad against Kennedy’s rivals, including Polis, did her no favors in the Democratic gubernatorial primary this spring.

“I think there would be a public backlash against Jared Polis. It would be seen as the dirtiest of politics,” Wadhams said. “I would think Polis would have to quickly condemn such an ad if it went up.”

In the end, Ciruli said, everyone on both sides of the race should remain alert to an incendiary and unpredictable issue like Klan affiliation popping up during what is expected to be the most expensive and hard-fought contest for governor ever in the state.

“Social media is just out of control today,” he said. “Both sides should be ready for it.”