The problem with gerrymandering in the US electoral system could theoretically be resolved with ”equalizing seats”. In Sweden, 10% of the seats in the Parliament are reserved as such seats. To figure out a completely proportional distribution the whole country is treated as one electoral district. Then the equalizing seats are distributed so as to compensate those political parties which have been disadvantaged by the sizing of the actual electoral districts.
Of course to implement a similar change in the US the constitution would have to be amended. Whether this is doable or not is another question.