How is threatening or using the filibuster "abusing" senate rules?
And of course the Repubs used it more because:
A) The Dems have/had 59-60 votes in the senate, with 2 moderates, while the Repubs only ever went up to 54 votes which includes enough moderates to go below 50 for reliable support on anything Conservative
B) The Repubs were largely ineffective and proposed nothing radical, even the Iraq war was mainstream for its time, whereas the Dems are trying to pass trillion dollar social welfare spending initiatives like "healthcare reform" or yet more massive bailouts that are adding far more than the usual bad amounts to the debt