(CNN) - Democratic Sen. Claire McCaskill's 84-year-old mother, Betty Anne Ward McCaskill, died on Monday, the senator from Missouri said in a statement on Monday.
"For some time, mom's health has not been good, and our family takes comfort that she is now at rest," McCaskill wrote. "People all over the state have asked about her, and their prayers and concern have been greatly appreciated."
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While Betty Anne McCaskill had her own place in politics as the first woman elected to the Columbia, Missouri City Council, she also regularly appeared on the campaign trail and in campaign advertisements.
McCaskill spoke on behalf of health reform at some of her daughter's 2009 health care town hall meetings.
As a mother, McCaskill may have planted the early seeds for her daughter's involvement in politics. "At Halloween in 1960, Betty Anne taught her children to say 'trick or treat and vote for JFK,' as they went door-to-door asking for candy," an obituary distributed by Sen. McCaskill's campaign read.
She is running for reelection to a second term and is being challenged by Republican Rep. Todd Akin, who issued a statement on Monday.
In a statement, Akin said, "Lulli and I want to express our deepest condolences to Claire McCaskill and her family. Our thoughts and prayers are with the whole McCaskill family right now."
McCaskill had limited her campaign schedule since her mother's hospitalization in St. Louis earlier this month.
– CNN's Kevin Liptak, Gregory Wallace, and Justin Lear contributed to this report