A good amount of people of color remember that Joe Biden was behind the 1995 three-strikes bill that heavily penalized nuisance crime, that he was behind the 2005 bankruptcy bill that made it impossible to have student loans written off in bankruptcy, and he was vice president in 2008 when Obama let the banks off with taps on the wrist after wrecking the economy. Oh, yes, the War On Drugs, too. Lots of people with a prison sentence over some marijuana.
It's not that Trump had a track record of doing things that benefitted non-white people, it's that Biden has a sustained track record of actually causing serious harm and people have not forgotten.
This makes more sense to me than beaner's argument that minorities think they will directly benefit from Trump's policies. Also bear in mind that Trump previously fought against a Clinton, and the Clintons are supposed to be specifically popular among some ethnic minorities.
It's not that Trump had a track record of doing things that benefitted non-white people, it's that Biden has a sustained track record of actually causing serious harm and people have not forgotten.