Sarah Palin's presence in the Alaska race and her support for Joe Miller was key, reports CBS News senior political correspondent Jeff Greenfield. Even though her resignation as governor hurt her standing in Alaska, she is popular among Republicans.
There's also a "family feud" aspect at play. Palin defeated Murkowski's father for governor four years ago.
Also significant was a proposal on the ballot to require parents to be notified if a teenage daughter of theirs sought an abortion. That brought out a lot of social conservatives who have long had problems with Murkowski's abortion views.
But the most intriguing race in the country is in Florida. Republican governor Charlie Crist, facing certain defeat in the Republican primary, decided to run as an independent. He faces Marco Rubio, former speaker of the statehouse, and congressman Kendric Meek, a Democrat.
It's very possible that control of the U.S. Senate could depend on this race, reports Greenfield, because if independent Charlie Crist wins, it's not certain which party he would line up with in Washington next year.