Power discrepancies and mob rule are different things.

[edit: though it's correct that the Senate, like the EC, is not "popular", as every state has two senators, rather than a proportionate amount, like representatives]

That point in your edit is actually a pretty big deal. We're already in a situation where a majority of the Senate represents less than 20% of the country's population. Some people will (correctly) retort that the Senate was never intended to be popular in the way you used the word, but -- just like the Electoral College -- the significant concentration of population in urban areas is something that the founders almost certainly didn't foresee.

While "mob rule" may be an unfair term, not only did more people vote for the Democratic presidential candidate in 2016, there have been more votes cast for Democrats than Republicans as a whole not only in Senate races over the last decade but in House races, too -- the Republican majority there is protected by gerrymandering.