A marginally less-extreme option would be to start subdividing larger states.
The Constitution does not permit amendments to change the "equal" representation of states in the Senate, but we can even the playing field by making it easy for large states to subdivide for the benefit of the people.
Blue States are actually extremely blue cities surrounded by red counties.
If you split California into 10 states, most will be red.
Awesome idea: Texas can become four states, Northern California can become a state, Northwest Dakota, Northeast Dakota, and Upper New York can all become states too with equal Senate representation.
Or did you perhaps have some gerrymandering-esque idea to limit these 'benefits' to liberal metropolitan areas?