PORTSMOUTH, Ohio -- Republican John McCain prides himself on being a straight talker. But he resisted being dragged into a discussion Wednesday about insurance companies that cover Viagra but not birth control products.

"I certainly do not want to discuss that issue," the presidential candidate said when a reporter asked him about it on his campaign bus, the "Straight Talk Express."

A few seats away was Carly Fiorina, a top McCain supporter who stirred talk about the topic at a recent Washington breakfast with reporters. The former Hewlett-Packard chief executive, discussing consumer-driven health insurance, mentioned something "I've been hearing a lot about from women: There are many health insurance plans that will cover Viagra but won't cover birth-control medication. Those women would like a choice."

Fiorina is among McCain's most prominent female advisers, and seen by some as a possible choice to be his running mate.

When asked Wednesday if he had voted in the Senate against a proposal to require insurance companies to cover contraceptive products, McCain replied, "I don't know enough about it to give you an informed answer because I don't recall the vote... I don't usually duck an issue, but I'll try to get back to you."

Campaign spokesman Brian Rogers later said Fiorina was describing McCain's "vision for choice and competition in health insurance." He said McCain will open insurance markets "for greater variety and competition, allowing women to choose policies that fit their needs. An example is the choice for women to dump a policy that only covers Viagra for a policy that covers their real needs."

A Republican policy group said the Senate vote in question was a complicated matter that, among other things, would have supported using federal money to promote emergency contraceptives, which many Americans oppose.