A telephone request from the Obama Volunteers of Texarkana asking a Lufkin, Texas, woman to vote for Sen. Barack Obama has prompted an investigation of a perceived “death threat” against the presidential candidate.

But Jessica Hughes, who was questioned by the Secret Service about her alleged remarks, said the events were “like a high school rumor.” Hughes likened her interview by the Secret Service to being questioned by the “thought police.”

Hughes was interviewed Oct. 2 by two Secret Service agents at her home. The agents asked if she made the statement “I will never...