If “safe Democratic” states yield 204 electoral votes, they are only good for 32 senators. Meanwhile, “safe Republican” states are only good for 182 electoral votes, but provide 44 senators. That leaves 24 senators from 12 states that either side may win in presidential years. If both parties won all their safe seats, and they split the seats in contested states, we would see a GOP majority in the Senate of 56-44.Those 12 states "in play" are often referred to as "battleground states" because they are where presidential elections are actively contested. Conclude from the above the GOP has an advantage in the Congress, the Dems have an advantage for the presidency.
As Cost makes clear, putting checks on the tyranny of the majority was the framers' clear intent. They valued gridlock.