There are many plausible EA reasons to prefer the Democrats have control of the Senate. One example is that if the Republicans have a majority it is extremely unlikely we will get a serious climate bill. Of course, even if the Democrats have 50 seats and the tie-breaker they may not get rid of the filibuster and will have serious trouble maintaining 100% of their caucus. But the expected value still seems high to many EAs. This is an unusually high leverage situation where two races in January will decide control of the Senate.
Political races do not tend to be very neglected. And the EA community is not the only group of people who are very interested in winning these seats. However, it is unclear to me what is the most effective way to influence the races. The candidates are likely going to be flooded with donations. Who should people donate to? Is there any plausible case some EAs should go to Georgia? As I understand it the deadline for registering new voters is Dec 7th.
This is definitely a 'speculative' cause but it is empirically on the mind of many EAs I know.