They are not on the species list at
http://www.invasive.org
But going by the definitions of an invasive species, they certainly could be considered such.
This line in the definitions could well apply to Red Winged Blackbirds, at times.
"that disrupt by a dominant colonization of a particular habitat"
However, they too can be disrupted by other species such as, believe it or not, Marsh Wrens, and more believably, Yellow Headed Blackbirds.
I suspect that it is because of this that they are not on the invasive species list.