In control like not touching the steering wheel much, they could if they would but they won’t.
Best thing is less extremism which is great, worst thing is nothing really changes. They are happy keeping the defunct democracy where they share power with the Republicans, and both sides work mainly for Wall Street and the 1%.
Luckily there are more DSA people among Democrats now, so some things may improve slightly. But they do not have the power to make real changes, at least not yet.