Rove was the person the local officials went to make sure something was done about the ags they didn't like. Rove probably kept it from happening until after they lost the 2006 elections because he didn't want to chance it and he really thought they would keep both houses. After the 2006 election he started looking to 2008 election.
Or he kept it from getting to the president until after the 2006 elections. I do tend to believe the president actively agreed to the firings, but no way to prove it.
To me he is involved because he is the main conduit for getting a presidential decision.