Sure you can. Ideology js more than the people who follow them. If your principles are sound, you don't need the strong leader, as another one can take its place as long as they align closely enough with its values.

Thats how the left infects new people with their ideologies. Only difference is once they lose power the ideas have to compete until a new orthodoxy emerges. Hence why social justice is so radically against many of the old communist talking points.

On the flip side, the founding principles of conservatism more or less can remain the same so long as its system remains. Sure, populism can help, but no person is without sin and populism is not required to win. Besides, people have whims, ideas do not, meaning even with imperfect people, as long as their ideas are sound, you can point to accomplishments.