I don't mean actual product advertisements like what Trump is doing, but every single US president actively endorsed and defended the right of capitalists to steal surplus value, all while being paid by those same capitalists, which I think absolutely counts as shilling.

The democrats are at least sometimes trying/pretending to make profit extraction sustainable with environmental protection and labor laws that are designed to prevent actual labor organizing. They also undoubtedly have some other benefits like minority rights and slightly more predictable policy choices. If I were in the US, I'd probably vote for dems in every election as a matter of harm reduction. But I also understand dems won't save US from corporatism/fascism, because they are by design servants of the capitalist class.