The American Prospect conducted an extensive analysis and Indian tribes reduced giving to Democrats after hiring Abramoff. This is a GOP scandal.
The analysis shows that when Abramoff took on his tribal clients, the majority of them dramatically ratcheted up donations to Republicans. Meanwhile, donations to Democrats from the same clients either dropped, remained largely static or, in two cases, rose by a far smaller percentage than the ones to Republicans did. This pattern suggests that whatever money went to Democrats, rather than having been steered by Abramoff, may have largely been money the tribes would have given anyway.