Do you think gay marriage would have been protected?
Access to birth control secured?
Anti-sodomy laws getting struck down?
The Affordable Care Act passing?
Disability rights?
Do you think any of those things would have happened if Republicans been able to seize power and hold it unopposed over the last 50 years? No. None of those things would have happened. Those things happened because people further left than them got elected, the lesser of 2 evils won some elections.