You mean proposition... but I don't agree, because online poker is substantially different from physical racetracks.
There's no infrastructure cost to the state from online gaming, while racetracks come with a lot of physical structure and support needs - space, parking, utilities, traffic...
Electronic tracking and collections of the revenue is also easier than tracking everything at the tracks.
This one seems to me to be a low-hanging fruit, as far as state revenue generation is concerned!