Simplify the following text for a Grade 9 native English-speaking person.
Original: In the past , this meant that senators represented various geographic regions within a state , regardless of the population , as a way of balancing the power of the lower house , which was apportioned according to population .
Simplified: In the past , this meant that senators represented different regions within a state , not according to the population of the region . This was a way of balancing the power of the lower house , where the numbers for each state were related to the state 's population .