The ascension of Donald Trump was supposed to change everything in the GOP. As it happens, perhaps one very important thing hasn’t: The Republicans may well still be The Stupid Party.

That Obamacare repeal has one or maybe two feet in the grave, depending on how you’re counting, is testament to jaw-dropping disarray and bad faith.

On the cusp of a historic failure, the party has begun the finger-pointing, and it’s hard to argue with any of it. The establishment is right that Trump is incapable of true legislative leadership. The Trumpists are right that the establishment is ineffectual. Conservatives are right that moderates don’t really want to repeal Obamacare, whatever they’ve said in the past. And pragmatists are right that a few conservatives are beholden to a self-defeating purity.

The Republican members of the world’s greatest deliberative body aren’t covering themselves in glory. Susan Collins of Maine and Rand Paul of Kentucky have always been noes, leaving no margin for error. Mike Lee of Utah and Jerry Moran of Kansas are additional noes on the current repeal-and-replace bill, while Shelley Moore Capito of West Virginia and Lisa Murkowski of Alaska have joined Collins as noes on repeal-only.

At least Collins, an ideological outlier in the Republican Conference, has been consistent. She voted against the repeal-only bill in 2015, and the GOP leadership never thought she was gettable. The same can’t be said of her cohorts. Capito and Murkowski both voted for the repeal-only bill a year and a half ago. The only plausible reason they’ve switched now is that they knew the bill would be safely relegated to oblivion by a Barack Obama veto, whereas Trump will now sign any legislation into law.

Then there is another tranche of Republicans, like Rob Portman, who are nervous fence-sitters. The Ohio senator doesn’t have to appear on a ballot again until 2022, yet gives every indication of quailing at taking a tough vote.

For Rand Paul, clearly, a perhaps once-in-a-generation opportunity to significantly reform two entitlement programs isn’t as important as scoring cheap points against his colleagues in the cause of getting as many cable hits as possible.

Lee is a thoughtful, public-interested conservative who isn’t a showboater. He has an outsize influence on the prospects of the bill because he is one of the few Republicans willing to be the decisive vote against it. This is why it’s particularly important that the Utah senator keep the big picture in view; torpedoing the entire effort over a relatively technical question about the insurance risk pools — Lee’s current posture — would be a disastrous mistake.

It’s not just senators who are falling down. President Trump has very little idea what is in the health care bill, and doesn’t particularly care. This prevents him from helpfully engaging in detailed negotiations, and he hasn’t made a public case for the bill except in tweets and at the highest level of generality.

Repealing Obamacare was never going to be easy. The law has created facts on the ground that are inherently difficult to undo. Mitch McConnell has 52 Republican senators, whereas Harry Reid had 60 senators. But Reid held all his members.

At the end of the day, the most important difference between the parties on health care may be that the Democrats had a vision that they were thoroughly committed to and were astonishingly courageous in effecting. No one had more to lose from sticking with the forced march toward passage of Obamacare than Nancy Pelosi, and yet no one was as devoted to the cause. If she becomes speaker again in 2019 after Republicans — disunited, selfish and fearful — have whiffed on repealing her handiwork, it will be the sweetest revenge.

Like the Democrats in 2009, Republicans have a historic opportunity that will quickly vanish unless it is seized. A majority is a terrible thing to waste. Six months in, Republicans are giving every indication that is exactly what they might do, to their everlasting disgrace.

Rich Lowry is a syndicated columnist. He can be reached via email at: comments.lowry@nationalreview.com.