It never, ever, hurts to write to your federal representative and senators. They and their staffers do listen and their votes directly determine the funding and oversight for NSF, NASA, and DOE.
I don't have great advice for direct advocacy (A billboard that says, "America's scientific infrastructure is collapsing -- fund science now!"?). At the grassroots level, providing opportunities for people to engage directly with science -- outreach, lab tours, science field trips, etc. help people to learn to understand the world around them, engage with science, see the infrastructure, and take ownership.
Every time I have given a lab tour, I thank everyone who attends for underwriting the science with their tax dollars. Essentially all fundamental research in the US is funded by you, the taxpayer. We are really, really grateful for the opportunity to learn something new about nature and share it with everyone. Thank you.
Not to digress too far but the general public at large won't even push to get funding for their own direct interests (e.g. COVID related stimulus right now). I don't know how we expect to get the general public to push for science.
Much of our society runs on pure momentum and very few people have the power to slightly shift the direction of that momentum.
One of the other large radio astronomy observatories in Greenback is also hurting for funding from what I understand. I've worked on a few collaborative research efforts utilizing the data and working with the observatory and the picture painted doesn't look promising there either. That may have changed more recently given the state of Arecibo.
It would be nice to fix the societal issue that ties up people's self-worth, status and sheer survival with their job, but that's a much bigger ask. Now you're into things like universal healthcare, UBI, mental health, education, etc. Still, we should work towards improvements on all fronts.
I think that in today's world, if you want science to get funded like defense projects, you'll have to embrace all of the grossness of defense projects. Lobbyists, sub-contractors, patriotic jingoism, fear, etc. Look at how we got to the moon.
