I am surprised it’s that close in registration. But I believe the Asian vote has gone heavily for the Dems since Clinton. As Asian immigration continues, this pro-Democratic trend is almost guaranteed to continue.
High levels of immigration (even if it is all legal) reinforces and strengthens all of the factors that lead immigrant communities to vote Democratic in the first place. As long as immigration levels are high, the GOP has no chance with Hispanics and Asians.