It is fair to say that Obama viewed terrorism as his greatest international short-term problem, the rise of China as our greatest long-term issue, and Russia as a nuisance. For the most part, he treated the Russians as just a declining regional power, to be resisted at times and accommodated at others. Putin’s ambitions are greater than that, so relations between the two countries suffered.
The Democrats clearly (and correctly) see political advantages in publicizing the weird ties between Trump and his base on the one hand and Putin on the other. The danger is that they may start to believe their own rhetoric when they return to power. Russia is a genuine danger, yes. But, for the reasons I described a few days ago, it is not the same kind of existential threat as the USSR, and should not be treated as one.