If you want to criticize Democrats, they did choose to expand Medicaid and Medicare without a more comprehensive long-term financing plan. OTOH, unlike the GOP tax reform, these expansions were at least nominally revenue neutral thanks to some targeted tax increases, the insurance mandate, etc. Democrats may spend but they _tax_ and spend, which is better than spending or (as Republicans do) cut taxes and spend.
Republicans could come to the table and attempt to compromise with Democrats. Democrats would want to expand benefits. Republicans would like to cut them, at the very least, if not eliminate benefits or privatize the entire program. But compromise theoretically could be fairly easy. But Republicans are committed to a nihilistic "starve the beast" strategy. That's the crux of the problem. Republican ideology has become so extreme that compromise is literally anathema. It's no coincidence that old-school Republicans have been bowing out left-and-right.
I see similar trends happening on the left with an insistence on single-payer healthcare, but it's early and not even remotely comparable to where Republican politics is at.
So no, it’s not one party - it’s both. And that’s what the problem is.