Vice President Kamala Harris officially conceded the presidential race to President-elect Donald Trump. But in places like Arizona, votes were still being counted Wednesday to decide several other hotly contested downballot races.Former television news anchor and staunch Trump supporter Kari Lake is going up against Democratic U.S. Rep. Ruben Gallego for Arizona's open seat in the U.S. Senate, which is being vacated by Democrat-turned-Independent Sen. Kyrsten Sinema.RELATED STORY | Arizona votes to enact new constitutional abortion protectionsAs of Wednesday afternoon, polls showed Gallego with a razor thin lead over Lake, with about two-thirds of the vote share in. But when will we know who won and what's taking so long?Arizona election officials warned before Election Day that it could take up to two weeks for the results to be tabulated in the state. In addition to a hefty turnout this election, the ballot is also two pages long in places like Maricopa County, the state's most populous county.But regardless of who wins Arizona's open seat in the U.S. Senate, they won't be able to swing the balance of power in the chamber. Heading into Election Day, Democrats were in control of the Senate by a 51-49 margin when including four independents who caucus with Democrats. But for the first time in four years, Republicans have wrestled back control.RELATED STORY | When we'll know who will gain control of the House of RepresentativesRepublicans flipped Senate seats away from Democrats in West Virginia, Montana and Ohio on Tuesday. That means Republicans will hold at least 52 seats come 2025, with the possibility of picking up several more when all of the results are settled.Meanwhile, it still remains to be seen which party will take control of the House of Representatives. Should the House flip blue, Democrats will be able to keep Trumps power in check during his second term as president. But should the GOP maintain its slim majority, a trifecta of Republican control will be in play next year, allowing Trump to more easily execute his agenda.