I'm not going to argue whether Amazon (and other online merchants) should be forced to collect sales taxes in California, whether it's an ethical or legal respo

I'm not going to argue whether Amazon (and other online merchants) should be forced to collect sales taxes in California, whether it's an ethical or legal responsibility, but it's definitely in California's interest to do so, and not just in the obvious way. The obvious benefit for CA is that it can collect more sales taxes from online purchases from companies like Amazon who have historically not collected the taxes. But a less obvious benefit is that it tilts the playing field so that merchants currently based in CA are better off (relative to itself without the tax) competitively. Additionally, companies that have avoided presence/nexus in California for the sole purpose of avoiding the tax will have less disincentives for avoiding California. As a result, perhaps more companies will open branches in California, either for sales, distribution, or development; and merchants already with presence in California will do relatively better than otherwise. I can see why California would want to push for such a tax.