The spread of the coronavirus — which has sidelined roughly 10 percent of the agency’s core security team — is believed to be partly linked to a series of campaign rallies that President Trump held in the weeks before the Nov. 3 election, according to the people, who, like others interviewed for this report, spoke on the condition of anonymity to describe the situation. …
Trump went on a travel blitz in the final stretch of the campaign, making five campaign stops on each of the last two days. On Nov. 2, Trump’s campaign schedule required five separate groups of Secret Service officers — each numbering 20 to several dozen — to travel to Fayetteville, N.C.; Scranton, Pa.; Traverse City, Mich.; and Kenosha and Grand Rapids, Wis.; to screen spectators and secure the perimeter around the president’s events. President-elect Joe Biden made two campaign stops that day that also required Secret Service protection, but in smaller numbers.
The agency is also examining whether some portion of the current infections are not travel-related, one government official said, but instead trace back to the site where many Secret Service officers report for duty each day: the White House.