Obama is visiting Denmark next month -- did Trump fear being overshadowed by him?
President Barack Obama laughs during a meeting in the Oval Office, Jan. 24, 2011. (Official White House Photo by Pete Souza)

President Donald Trump on Tuesday night abruptly canceled his plans to meet with Denmark's prime minister because the Danish government has said it will not sell him Greenland.

However, anti-Trump conservative David Frum is speculating that there may be a hidden reason for the president's decision to back away from meeting Denmark.

As Danish newspaper The Local reports, Obama is scheduled to visit Denmark in late September during a talk at the northern city of Aalborg.

Frum speculates that Trump is "scared of the likely contrast to his state visit," which would likely have been marked by angry protests and public rebuffs to his proposal to buy Greenland.

"In his self-loathing heart, Trump knows Obama is bigger than he is, around the world as well as in the United States," writes Frum. "That knowledge tortures Trump, never allows him a minute's respite."

The Washington Post's Greg Sargent believes Frum's theory has some merit and he points to past incidences where Trump has delayed traveling overseas for fear of being met by protesters.

"Trump’s hypersensitivity to how he’s received extends abroad, too: After his trip to London, Trump claimed that large protests there simply never happened," Sargent writes. "So it’s at least plausible that one of Trump’s considerations in canceling the Denmark trip was Obama’s planned visit."