There is a reason that, despite the candidates, just about every American presidential election splits roughly 50/50 Democrat and Republican. An individual's inclination toward liberal vs. conservative values is largely genetic, and these psychological predispositions are products of evolution. Both liberal and conservative ideologies have survival advantages, depending on the situation, so nature ensured there would be approximately equal numbers of both.
Contrary to liberals' strawman view, the role of conservatives is not to “roll back rights” — it is to try to conserve existing rights and the policies that have created an ordered and functional society. This also means preventing liberals from making new changes to the rules of society (aka your tribe) that would disrupt that functionality and order. This push and pull of liberals and conservatives is largely healthy for society—that is if the left and right have equal power.
No one knows if any given change (or progressive policy) will work to make society better, or if it will lead to destruction and the end of that society. This is why both liberals and conservatives are needed. Conservatives fight to prevent making changes while liberals fight to make changes (or become more progressive). Despite good intentions, a new change may have negative consequences. And despite relative functionality, a disruptive change may increase the functionality of society. Neither side can predict the future.
The push and pull of liberals and conservatives ensures only minor changes to society are made at a time, and if the new policy works, conservatives will accept it and it becomes a part of the functioning society. Inevitably liberals will want to then make another change — push the boundaries even further. And of course, the conservatives have to protest because they don't know if the changes will have negative effects and ultimately lead to the destruction of society.
Conservatives can recognize if a new policy doesn't work. Society (the voters) will backlash and influence politicians to roll back that policy to the way things were before when society was more functional and ordered. An example is the 1960s when the culture shifted too liberal too fast with the psychedelic hippie movement and society became too chaotic, which resulted in Regan and the War on Drugs. This cycle continued: Obama was a response to Bush, and Trump was a response to Obama.
Evolution ensures there are roughly equal numbers of conservatives and liberals in society (just as it does males and females) to serve as a yin/yang equilibrium. The liberal/conservative balance of a civilization is an evolutionary safeguard to make sure the civilization builds and expands without becoming too liberal or too conservative (aka too chaotic or too ordered), neither of which is ideal. A healthy society needs a balance of both.
As stated earlier, the key is that liberals and conservatives must hold roughly equal power. When one side gains too much power over society, they can prevent the other side from pushing/pulling, or keeping them in check, then society becomes too chaotic/oppressive. But no side can maintain a monopoly on power forever. Eventually it will break with a revolution from the other side. This is the way human society has progressed throughout history and it will continue to do so into the future. Liberals and conservatives fight each other while making small incremental changes to society. The cycle continues over and over again, forever.