Major forecaster FiveThirtyEight gives Democrats nearly 70% chance of winning Senate in November

Democrats have a modest edge at winning the U.S. Senate in November, a major election forecaster is claiming, with Republicans looking at several losses in key races that could throw majority control of the upper chamber to the president's party next year. 

Democrats "currently have the lead in the race for the Senate," FiveThirtyEight said this week, citing in part "a few key races" where "Republicans have selected weak candidates, hurting their chances of taking the chamber in November."

The forecaster said it had run an election simulation "40,000 times to see which party wins the Senate most often." Under those simulations, Democrats won control of that chamber 69 times out of 100. 

Democrats "have an 80% chance of holding between 47 and 54 seats," the site said.

A 54-seat Democratic majority would place the Senate firmly in Democratic control; as of right now the seats are divided evenly between both parties, throwing any tiebreaking votes to Vice President Kamala Harris, who in her constitutional role also serves the president of the Senate.

Analysts have speculated that several issues such as the repeal of Roe v. Wade may generate sufficient liberal backlash to throw multiple races in favor of Democrats this year, though historically midterm elections often see significant losses for the parties of incumbent presidents.