Steve Ellner, a political science professor at Johns Hopkins University in Baltimore, said he thinks one significant hurdle facing Capriles is to try to "challenge Chavez's claim to being the president of the non-privileged as well as the defender of Venezuelan nationalism."

"Capriles needs to come up with a set of concrete measures that are innovative and reach out to the popular classes," Ellner said.

Capriles is a moderate who describes his views as center-left.

He said he expects personal attacks from Chavez to increase, and suggested that he, too, might become more confrontational in response. So far, Capriles has largely avoided direct or personal barbs.

Capriles said he's ready to confront Chavez, but wants the discussion to focus on issues related to Venezuela's most pressing domestic problems.

"If they want me to get into the ring, I'll get into the ring, but my objective is knocking out corruption, unemployment, the hospital infrastructure that doesn't function," Capriles said.

Capriles said he would welcome a televised debate. Chavez didn't immediately respond to that challenge.

The leftist president said before the primary that all of his rivals represent the interests of the rich and the U.S. government.

Chavez has already kicked his campaign machinery into gear. He has increased spending by launching new social programs that offer cash benefits for the poor and invested heavily in new railways, public housing and cable car systems in Venezuela's hillside slums. As the election nears, he will inaugurate other big-ticket projects that grab attention, including the planned launch of Venezuela's second Chinese-made satellite shortly before the October vote.

Capriles might not be able to compete with Chavez's spending nor his ability to take over the airwaves of all TV and radio stations when he deems appropriate. But Capriles can count on ample campaign funding from anti-Chavez donors, as well as high visibility in opposition-aligned media including the television channel Globovision, private radio stations and newspapers.

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