The costliest congressional election in U.S. history was headed for a photo finish on Tuesday as Democrats hoped dissatisfaction with President Donald Trump would help them win a suburban Atlanta seat that has been held by Republicans since the 1970s.

Democrat Jon Ossoff and Republican Karen Handel have both focused on local concerns, but national political groups have spent heavily in the biggest proxy war between the two parties since Trump’s upset victory in the 2016 presidential election.

This time, Republicans are playing defense. Ossoff, 30, aims to win a district that has launched the careers of nationally known Republicans like Newt Gingrich.

Recent polls show a tight race, with Ossoff maintaining a tight lead over Handel.

Total spending in the race has topped $56 million, according to the Center for Responsive Politics, a watchdog group, nearly double the previous record.

An Ossoff victory would help Democrats raise money and recruit candidates as they try to win back control of the House of Representatives in 2018.

“There are more of us than we thought,” said Tricia Gephardt, an Ossoff volunteer.

Ossoff gained national prominence by vowing to “make Trump furious,” but lately he has avoided mentioning the president.