By JULIA PRESTON
WASHINGTON, Mich., June 8 — The undoing of the immigration bill in the Senate this week had many players, but none more effective than angry voters like Monique Thibodeaux, who joined a nationwide campaign to derail it.

Mrs. Thibodeaux, an office manager at a towing company here in suburban Detroit, became politically active as she never had before. Guided by conservative Internet organizations, she made calls and sent e-mail messages to senators across the country and pushed her friends to do the same.

“These people came in the wrong way, so they don’t belong here, period,â€