There is a lot of money in the federal budget already that could be better spent. Much of it already goes to the safety net - medicare expenses, social security, unemployment and housing subsidies. Yes many of these programs could use bigger budgets, but a lot of what keeps it from getting into people's hands is bureaucratic overhead and bad systems, delays signing up, having to call repeatedly for weeks before you can get a hold of somebody to process your application, etc. Those things shouldn't be particularly expensive to improve if it were prioritized.
The well-documented ballooning healthcare costs make medicare more expensive in addition to hitting many citizens directly, so improvements there would have a huge impact.
Of the rest of the budget much of it goes to the military which doesn't seem to be particularly efficiently spent either in recent decades.
If more revenue really is the answer, I'm not opposed to bumping up taxes more in certain ways. I'm definitely for ideas that make taxes less regressive, for instance getting rid of the lower long-term capital tax rate is probably good idea and a simple way to raise effective tax rates on the wealthy in a massive way.
But you don't have to demonize those at the top so much to get any of this stuff done. Doing so is a major distraction, and I do genuinely worry about the self-fulfilling prophecy of drilling into everyone's head the highly exaggerated narrative that there is no hope for anyone else because the rich have completely rigged the system. And too often these days that seems to be what people focus on, rather than the hard work of making real, tangible improvements in the lives of those at the bottom.