PORTLAND, Ore. (AP) -- Former Vice President Al Gore is scheduled to visit Portland Oct. 24 to campaign for Democrat Jeff Merkley in a tight U.S. Senate race.

Since Oregon is not a presidential battleground, big-name politicians have been rare since before the national nominating conventions.

Gore recently campaigned for comedian Al Franken, another Democrat trying to oust an incumbent Republican, Minnesota Sen. Norm Coleman.

Brian Van Pelt/KTVB

Merkley is challenging Republican Sen. Gordon Smith.

Merkley touted Gore's leadership on climate change, saying climate change and investing in renewable energy are central to his campaign.

The event is at the Oregon Convention Center. General admission is $50.