Well, one day outside of Rorikstead my Dunmer Rogue was skipping along happy as can be, when I stumbled upon a Thalmor group. I walked up to see what' up, and they promptly told me to [censored] off or they'd ship my ass back to Vvardenfell in a crate. Now, I know that Bosmer and Altmer are not big fans of Dunmer (or Orismer), but they ARE Mer. So, why hasn't the Thalmor pushed their agendas into Morrowind? (From what I hear its somewhat recovered from the Red Year...)

Altmer and Dunmer have almost NEVER gotten along together. Why else would the Bosmer who helps you during the Thalmor embassy mission want to escape to Morrowind as Dunmer hate Thalmor.

The Dunmer are just about as diametrically opposed to the Thalmor as the mannish races are. They revere Lorkhan and do not view the mortal plane as a trap, which is the foulest heresy there is according to the Altmer. We have no idea what kind of agenda the Thalmor might have in Morrowind, though.

The Aldmeri Dominion/Thalmor are spread a bit thin, it hasn't been that long since the White Gold Concordat was signed... and the Dunmer are already beat down pretty bad after the double whammy of Red Mountain exploding and the Argonians invading (quite possibly egged on by the Thalmor to do so).

As already stated, the Dunmer and Altmer ain't buddies. They had their schism absolutely ages ago.

Speaking long term, the Aldmeri/Thalmor will eventually have to subjugate what's left of the Dunmer and abolish their "heretical" worship, but it's not like they can just go march into Morrowind right now.