Stuart “Toby” Pennels, a former Army colonel from Casco who hoped to serve in the state Legislature, died early Thursday from injuries he sustained in a motorcycle accident a month ago near Rangeley.

Pennels, 55, was set to run for Maine’s Senate District 26 seat in November. A Republican, he was expected to run against Democrat Bill Diamond.

Pennels had been hospitalized in critical condition since Aug. 3, when he lost control of his motorcycle and was hit by a pickup truck on Route 4 in Sandy River Plantation.

Pennels was wearing a helmet, but suffered severe chest and shoulder injuries and was taken by LifeFlight helicopter to Central Maine Medical Center in Lewiston.

“It’s been a horrific 32 days for our family,” said Brenda Pennels, his wife. She and their three adult children, Taylor, 27, Jordan, 24, and Shawn, 22, were with him at the Hospice House in Auburn when he died at 12:15 a.m. Thursday.

She announced his death in a post on a page set up for her husband on caringbridge.org, where thousands of people who knew Toby Pennels had left messages.

“Toby was at the top of his game when this accident happened,” Brenda Pennels said in a phone call Thursday evening. “He stepped out of his life at the busiest time of his life and the happiest time of his life.”

Brenda Pennels said her husband owned an independent financial planning business that was thriving, their marriage was stronger than ever after 31 years, and their three children had all graduated from college and gotten great jobs.

“This spring he decided, ‘I’m going to lose 30 pounds.’ And he did,” she said. “Everything was going well for Toby.”

Toby Pennels served in the Army and the Army Reserves, making two tours in Iraq, one in Bosnia and serving 32 months in a combat zone, according to his wife and a profile provided by the state Republican Party. During his last tour, he commanded a brigade in Baghdad. He retired from the Army as a colonel.

“He made a lot of decisions that saved lives, and he had soldiers who died in his arms,” Brenda Pennels said. “People all over the world who knew Toby, everybody who ever met him, has felt the need to reach out and share their story of how they met Toby.”

A graduate of Windham High School and the University of Massachusetts, he served 12 years on the Windham-Raymond School Board before his family recently moved to Casco.

His business, Penn Investment Services, specialized in long-term growth and stock portfolio management.

Gov. Paul LePage, along with his wife, expressed condolences for the family in a written statement.

“I conveyed our sympathies when I met with them last week, but we cannot imagine the grief they must feel,” LePage said in the statement. “At the same time, they should be very proud that their husband and father served our country with honor and always supported his fellow veterans. He was a devoted family man and a dedicated citizen who was willing to step up and serve his community.”

Maine State Republican Leader Michael Thibodeau of Waldo also praised Pennels in a statement.

“He will be remembered as a man whose unselfish dedication to his country and his community knew no bounds. Even after serving his country honorably in Iraq, coming home and running a business, and giving his time to local veterans groups, it was clear to all that Toby still had so much to give,” Thibodeau said.

Pennels was approved as the Republican Party candidate in late July after David Call, who ran in the June primary, withdrew from the race.

District 26 covers Baldwin, Casco, Frye Island, Raymond and Standish.

“I am certain he would have been an outstanding senator,” Thibodeau said.

As of Thursday night, the state Republican Party hadn’t announced a candidate to replace Pennels in the District 26 race against Diamond.