A new CBS News/New York Times Battleground Tracker estimate finds the Republicans positioned to take the Senate this year, with a likely 51-49 seat edge if the November election were held right now. The margin of error on that current seat estimate, at plus or minus 2 seats, means Democrats still have a real possibility to keep the chamber and that we head into campaign season with control up for grabs -- with a closely-divided Senate surely coming in 2015 in either case.
The data is based on more than 100,000 interviews conducted online for CBS News and the New York Times by YouGov exclusively as part of this joint project, with samples for every individual Senate race and House race, oversamples in competitive races, and each matched to the demographics and voter characteristics in the states and districts.
The current Senate is 55-45 Democratic.