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A quick head's up on what this is. The Battleground is an aggregation of NPR member stations' content produced during election night. It's curated by the staff at NPR Digital Services, including Eric Athas, Teresa Gorman, Will Snyder, Kim Perry and Erin Teare Martin. The list of participating stations and states is posted at the bottom.
For Republicans itching to regain control of the Senate, Tuesday's election presents a rare opportunity. Only 10 GOP incumbents are on the ballot, compared with nearly two dozen Democrats and independents who caucus with them.
That means the magic number for Republicans is low. They need only a net gain of three or four seats to take over the Senate — and, assuming they keep the U.S. House of Representatives, consolidate their influence on Capitol Hill. Democrats need to pick up 25 seats to seize the House, a goal that political analysts consider all but out of reach.