David Harsanyi just wrote a good article on the subject. Here's part of it:
Voters have many rational reasons to be furious with the GOP. But numerous times in recent anti-Trump appearances—in real life and in the media—I’ve been confronted by a peculiar allegation. Republicans, people tell me, were elected by the People and yet they’ve done absolutely nothing. Lately, this indictment has started to mutate into “Republicans gave President Obama everything he wanted.” The GOP and Obama were basically colluding against the American voter this whole time.
Mostly the claim seems to be a way to rationalize abandonment of principles to support Donald Trump—who, need it be said, is far to the left of any of these supposed GOP apostates. But I’ve heard Ted Cruz fans make similar arguments. It’s a big myth.
Republicans have been dreadful on plenty of fronts—the quality of their advocacy, the spine they show making arguments, and the lack of innovation and malleability in the focus of their policies, to name a very few—but resistance to Obama’s legislative agenda was definitely not one of them. If Republicans had capitulated in the way the average angry populist claims, Obama would not have needed to enact some of the most consequential abuses of executive power since World War II.
Some of this anger is propelled by false expectations and wishful thinking about how government works—which is to say, when voters don’t get what they want they assume the system has failed. On one hand, voters are under the impression that presidents should be able to craft law and policy and make everything great again; and, on the other, they are angered about the ineffectiveness of the legislative branch. It all depends on which of these corresponds with their own political affiliation….
Now, imagine what the past few years would have looked like if the GOP had participated in passing gun-control legislation and supporting higher energy prices. To be fair, Trump now, in one way or another, supports most of these progressive ideas, and his cultists are perfectly willing to bend their own outlook to match his. But, at the time, “compromise” on the Obama agenda would have created a different kind of turmoil for Trump to take advantage of, because he is not bound by any principled positions.
Fact is, Democrats got some of the things they wanted. But not all, or we’d be dealing with single-payer health care, carbon-trading energy markets, more union bailouts, and about a dozen reforms that you don’t even know exist.