On Friday night, 12 senators missed the vote to expand the Foreign Intelligence Surveillance Act, while 13 House members did not vote on Saturday and Sunday morning.

Rep. Dennis Hastert (R-Ill.) was flying to Japan for a meeting with the speaker of the Japanese House of Representatives. Hastert will also be traveling to China, press secretary Lulu Blacksmith said.

Sen. John Kerry (D-Mass.) missed Friday’s votes to ride in a charity bike race across Massachusetts. Kerry is a prostate cancer survivor and this year helped raise $25,000 for cancer research.

Kerry spokeswoman Amy Brundage said Kerry strongly opposed the FISA measure and “was prepared to return to the Senate if he was able to affect final outcome of the FISA vote.”

Rep. Howard Coble (R-N.C.) missed the votes to attend meetings with constituents in North Carolina. “He asked leadership and they said his vote wouldn’t be critical to the outcome of any particular bill,” press secretary Edward McDonald said.

Many members missed votes to attend family functions out of town.

Rep. Jim Saxton (R-N.J.) was attending a birthday party for his 90-year-old mother in Pennsylvania.

“It had been on the books for a while and he did not expect that Congress would be in session into the morning on Sunday,” communications director Jeff Sagnip said.

Rep. Robin Hayes (R-N.C.) attended his mother’s funeral, spokesperson Amanda Little said.

Others were more vague.

Sen. Lamar Alexander (R-Tenn.) was “unavoidably absent” because of a family commitment, his press secretary Lee Pitts said, adding that the senator submitted a statement for the record about how he would have voted.

Sen. Patty Murray (D-Wash.) had a family commitment that the leadership was aware of, spokeswoman Alex Glass said.

Rep. Ron Klein (D-Fla.) also had a family commitment that “was not flexible,” spokeswoman Adrienne Elrod said.

Some members weren’t able to vote because of health issues.

Rep. Ander Crenshaw (R-Fla.) underwent surgery to correct a spinal condition that was causing pain in his back and leg. Spokesman David Taft said the surgery was successful and the congressman will return to work after he recovers.

Rep. Jo Ann Davis (R-Va.) is recovering from breast cancer surgery. Rep. Yvette Clarke (D-N.Y.) is recovering from surgery to remove a non-cancerous growth in her uterus.

Rep. Sam Johnson (R-Texas) was in Plano, Texas recovering from knee surgery, spokeswoman McCall Avery said.

Sen. Tim Johnson (D-S.D.) continues to recover from a brain hemorrhage. Johnson spokeswoman Julianne Fisher said they are hopeful the senator will return to work early this fall. 

Eight other senators missed two key votes Friday: Sen. Barbara Boxer (D-Calif.), Sen. Jim Bunning (R-Ky.), Sen. Byron Dorgan (D-N.D.), Sen. Judd Gregg (R-N.H.), Sen. Tom Harkin (D-Iowa), Sen. Trent Lott (R-Miss.), Sen. Richard Lugar (R-Ind.) and Sen. John McCain (R-Ariz.). Spokespeople for the senators did not return calls for comment.

Spokespeople for Rep. Lacy Clay (D-Mo.), Rep. Ray LaHood (R-Ill.), Rep. Ron Paul (R-Texas) and Rep. Ike Skelton (D-Mo.) also did not return calls and e-mails for comment. The representatives did not vote Saturday or Sunday.