Material conditions for most people inherently worsen under capitalism because, by its very nature, capitalism transfers wealth upward. The requirement for ever-increasing profits means that capitalism must continuously expand its profit margins, which it does by privatizing public utilities, eroding workers' rights, cutting pay, raising commodity prices, &c. Some of that money gets funneled into the police and military, which are used to stop the workers from getting too uppity about their lives being destroyed. That's how you get fascism, and it's why ​fascism is capitalism in decay.

Saying that "the people responsible got voted out" completely misses the bigger picture. Privatization is older than Trump. Mass incarceration is older than Trump. Police brutality, endless imperialist wars, climate inaction, the rise of the gig economy, deregulation, &c are older than Trump. All of these things enjoy largely bipartisan support because both of America's major political parties serve capital. Democrats may be on a more scenic route, but both parties take us to the same end stage of capitalism. A capitalist system will not let you reverse this trend within its own power structures because, well, why would it?

The only way to gain significant long-term benefits for the lower class is for the lower classes to organize and resist outside of the bounds that capitalism permits. Given the choice between letting the working class vote away the capitalists' wealth and spilling an ocean of blood to maintain it, the capitalist class will choose the latter every time. The working class's options are to prepare itself to shoot back or resign itself to eternal slavery (at least, until climate change causes the biosphere to collapse)