Since the basics of the ACA are identical to plans Republicans put forth multiple times over the past few decades, the downside is Republicans will be caught in

Since the basics of the ACA are identical to plans Republicans put forth multiple times over the past few decades, the downside is Republicans will be caught in the trap of being violently against something that was both A) their idea originally and B) has been shown to be quite popular among voters once they learn what it actually does. Thus the Republican party has committed to stopping implementation at all costs.