For both parties, the only constituencies they really care about are big businesses. The big corporations backing republicans are benefitted by a smaller gover

For both parties, the only constituencies they really care about are big businesses. The big corporations backing republicans are benefitted by a smaller government, so that's what republicans advocate for. The big corporations backing democrats are benefitted by a larger government, so that's what they advocate for. (There are of course other non-corporate groups in play, e.g. unions, but the idea stands). Beyond that, there's a lot of overlap in what big businesses want, and that's were you get bipartisan agreement. Corporations generally care about drugs in the sense that they want a labor pool that's not on drugs, so both parties kowtow to them on this topic. Parties will pay lip service to the wedge issues of the day, but ultimately the parties do not actually concern themselves with the common voter except to make the appropriate sounds that those voters want to hear.