HELENA — Sen. John Walsh was taking personal time at his Helena home as his campaign canceled events and avoided questions about whether the Montana Democrat plans to remain in the U.S. Senate race amid allegations that he plagiarized a research paper.

Walsh was scheduled to be at a Jackson, Wyoming, fundraiser Tuesday with Colorado Sen. Mark Udall, but did not attend.

His campaign also notified Gallatin County Democratic party members that the senator would not appear at a backyard meet-and-greet in Bozeman hosted by Women for Walsh that was scheduled for Wednesday, or a Friday talk on public lands at the county party’s new headquarters.

“He took a personal day yesterday,” campaign spokeswoman Lauren Passalacqua said Wednesday.

Nobody answered the door at Walsh’s home Wednesday. Passalacqua declined to answer questions about Walsh’s plans or the postponement of campaign events.

The campaign also provided no reason to the Gallatin County Democrats, said Billy McWilliams, a member of the county party’s executive committee.

“Nobody’s talking,” McWilliams told The Associated Press.

The Bozeman Daily Chronicle first reported the postponements.

Walsh has come under increasing pressure after The New York Times reported that he plagiarized portions of the 2007 research project he wrote while attending U.S. Army War College in Pennsylvania. The editorial boards of Montana’s three largest daily newspapers have called for him to withdraw his candidacy, while others have demanded that he apologize or that he forfeit his master’s degree.

“Instead of closing ranks around Walsh, Democrats should call on him to do the right thing,” The Billings Gazette wrote in a Sunday editorial. “Having repeatedly said that he wants to do the honorable thing, Walsh should stop campaigning and do his utmost to serve Montanans well in the remainder of his brief Senate appointment.”

The Montana Democratic Party continued to pledge its support of Walsh. “Senator Walsh is our U.S. Senator and candidate,” party spokesman Bryan Watt said.

Walsh is running against Republican Rep. Steve Daines to keep the Senate seat he was appointed to by Gov. Steve Bullock in February when Max Baucus resigned to become ambassador to China.

Bullock communications director Dave Parker said Wednesday the governor has not spoken to Walsh since the Times’ story was published.

Walsh previously said he made unintentional mistakes in not citing others’ work in his paper on the spread of democracy in the Middle East. He also said he was being treated for symptoms of post-traumatic stress disorder at the time, but said he was not blaming PTSD for his mistake.

Since then, Walsh’s campaign has gone dark. His website has not been updated since July 30, and his campaign staff last sent a news release Friday. Walsh’s normally active Facebook page and Twitter account haven’t been updated since the weekend.

Watt said the Democratic Party is not vetting potential replacement candidates, but party leaders are reviewing the steps they would take if Walsh decides to withdraw.

According to party rules, the Democrats would hold a nominating convention to select a replacement. Convention delegates would include county party committee leaders, party executive board members and statewide and federally elected officials — about 175 people, Watt said.

They would gather to nominate potential replacements and hold rounds of balloting until one person received a majority of the votes.

The Montana Secretary of State deadline for submitting a replacement candidate is Aug. 20.

Associated Press writer Lisa Baumann contributed to this report.