I'm not so sure that the math is that encouraging. Of the 600,000 deaths, by far the biggest portion happened before we had any vaccines, or when the vaccine had just come out (remember almost 2/3 of that total was before Biden got in office), and as you point out, it was people of color and citizens of urban areas that were disproportionately harmed. Even now, while a substantial majority of the anti-vaxxers are clearly Trump supporters, many, many of the un-vaccinated are still people of color and the urban poor, who are presumably not primarily voting Republican.

Putting that together, it is extremely likely that so far, in purple states like Georgia, North Carolina, Arizona, and maybe Wisconsin, the majority of deaths to date from COVID have been Democrats, not Republicans. Even if at this moment deaths skew Republican, with fatality rates of less than 1%, the coronavirus epidemic will have to go on for a very long time for the Republican deaths to equal Democratic deaths, even in the purple states. Which should make us very worried about Senate seats in the 2022 election.