Most Texans don't support succession and understand that it would not be legal (see: Texas v White 1868 for why that is). If Abbott is serious about trying it, the Metro centers and suburbs would almost immediately counter-revolt against them.
Abbott is a jackass lashing out at a world leaving him and his ilk behind. Texas is going to flip purple in the next five to ten years; the hardcore MAGA's know that and it terrifies them. Not if but when Texas becomes a swing state, even if it is only slightly competitive, that will flip American politics at the national level on its head. Republicans haven't had to worry about and spend national campaign money in Texas since the 1980's... they may not even have the party infrastructure to take on such a task at the moment. Democrats could ignore campaigning in other swing states like Florida, North Carolina, Pennsylvania, and the like to focus all campaigning on Texas... meanwhile Republicans would still need to spend in those other states while also having to spend money to defend a no longer solid red Texas. For them, this is a party-ending nightmare scenario... a set back on their hold on power lasting at least a generation.