The Democrats' chance of wresting control away from Republicans has increased over the last few months. They are clearer favorites to take back Congress' upper chamber, though the race for Senate control is still well within the margin of error.
To gain a majority of seats, Democrats need a net pickup of between three seats (if Biden holds onto his lead over President Donald Trump, as his vice president would become the tie-breaking vote) or four seats (if Trump wins).
Democrats now have a little more than a 7-in-10 (70%) shot to win at least 3 seats and a little more than a 6-in-10 (60%) chance of winning at least 4 seats. In early May, it was 3-in-5 (60%) for at least a 3 seat gain and 1-in-2 (50%) for a 4 seat shift.
But then as now, there's a lot of uncertainty. We still have three months to go before the election. Applying a margin of error (based on past performance), it's possible Republicans could retain control and potentially even gain a seat or two. Democrats, meanwhile, could run the table and have a double-digit gain.
The reasons Democrats are likely to do well remain the same as it was in May. They have a lead north of 8 points on the generic congressional ballot. Additionally, Democrats only need to defend 12 of the 35 seats up for election this year, so they continue to have a wide array of choices. They have at least a 1-in-10 (10%) chance in two dozen (24) seats. They likely won't win all of these seats, but even if they lose a bunch of them, they still have a real shot at a majority.
Democratic chances to win in a number of these races have gone up since May.
Specifically, Democrats are doing considerably better in a number of races that were either tossups or previously leaning toward the Republicans:
North Carolina was best described as a tossup in early May. The polling, however, has moved in Democrat Cal Cunningham's direction. Although Republican Sen. Thom Tillis is still very much in the hunt, Cunningham now has about a 2-in-3 (67%) chance of defeating the incumbent.
Iowa was a race that was leaning in Republican Sen. Joni Ernst's direction. The recent polling, however, has actually given Democrat Theresa Greenfield the smallest of edges. Given the Republican tilt of Iowa, Ernst could close. For now, the race is a tossup (1-in-2 shot for both candidates), as opposed to May, when Ernst was a 3:1 favorite.
Republicans now only have small advantages in both Georgia Senate races. Republican Sen. David Perdue has about a 3-in-5 shot (60%) of beating Democrat Jon Ossoff in the regularly scheduled election. That's up considerably from May thanks to Ossoff holding close to Perdue in the polls. In the special election (with multiple candidates on both sides running in a jungle primary), the Republicans have closer to a 2-in-3 (66%) chance. The Republicans had just less than a 9-in-10 (90%) chance back in early May.
Beyond those four races, Democratic odds have not gone up greatly in any state.
Democrats, though, are now favorit
