HARRISONVILLE, Mo. — On a recent Wednesday, when many teenagers here were doing homework or playing after-school sports, 17-year-old Ania Bishop, in an ankle-length skirt with American flags, was cheering at a political rally for Representative Todd Akin.

The rest of her family was there, too: her father and teenage brother, both in “Stand With Todd” T-shirts, and her 6-year-old sister, who sat cross-legged at her mother’s feet. They listened while Mr. Akin, the Republican seeking to unseat the incumbent Democrat, Claire McCaskill, in one of the year’s most closely watched Senate races, reiterated his anti-abortion stance to the approving crowd. The mother, Ellen Bishop, says she spends 10 to 15 hours a week working on Akin campaign matters, while her children put in about 6 to 10 hours. Because the children are home-schooled, she said, they can translate their campaign work into lessons.

As Mr. Akin, a six-term congressman, fights for his political life after making controversial comments about rape victims, he is counting on a coalition of home-schoolers as part of a crucial support network for his struggling campaign. Mr. Akin and his wife, Lulli, home-schooled all six of their children, and it was other such families who helped in his political rise. Now, after losing the backing and financing of much of the Republican Party establishment, he is counting on them — and other parts of his conservative, evangelical base — as never before for help in grass-roots fund-raising and in coordinating volunteers across the state.

Mr. Akin reaffirmed on Tuesday his intention to stay in the race as the deadline came and went for him to withdraw. To underscore his commitment, he began a statewide bus tour that will run through Friday and include an appearance by Phyllis Schlafly, the conservative activist. On Monday, he got help from Newt Gingrich, who, during a $500-a-plate lunch fund-raiser near St. Louis, encouraged fellow Republicans to support Mr. Akin.