Washington CNN  — 

Over the past 24 hours, President Donald Trump has taken two actions aimed at mortally wounding the Affordable Care Act.

The first tasks his administration with increasing competition among health care insurers, a move very likely to drive younger people out of the insurance marketplace entirely and driving up costs across the board. The second, announced late Thursday night, stops the federal subsidies being paid to insurance companies to incentivize them to cover lower-income Americans.

The key to understanding Trump’s motivations here are entirely contained in the ACA’s shorthand nickname: Obamacare. It’s named after the man – former President Barack Obama (duh) – who shepherded it into existence. And that’s exactly why Trump wants to get rid of it.

Trump’s entire political life – dating all the way back to his adoption of birtherism earlier this decade – is positioned against all things Obama. Why? Because for many Trump supporters in this country, Obama – and his beliefs about society and government – were the antithesis of what they believed. (Yes, Obama’s race – and multicultural vision of the country and the world – were part of that mix as well.)

The best way to distinguish yourself in Republican politics during Obama’s time in office was to position yourself against, literally, everything about Obama – up to and including his legitimacy to be president due to fact-free claims about where he was born.

Trump learned that lesson sooner and better than any of the Republican politicians who were running for president in 2016. (It also helped that he was willing to say things about Obama that no other Republican politician would.) Every move Obama had made since winning in 2008 was not just wrong to Trump’s mind, but – and this is super-important – un-American. Obama didn’t understand what made America the single greatest nation in the world (faith in its people and the free market). Trump did.

Trump also grasped early on that the symbolic center of Obama-ism – the thing that conservatives hated most – was Obamacare. It was the classic liberal solution: Put the federal government at the center of your life and insist it, not you, knew better about the best way to look after you and your health.

At every rally, every speech and almost every day on Twitter during the 2016 campaign, Trump promised to get rid of Obamacare – and quickly.

 “We’re going to repeal  and replace Obamacare,” Trump said at a Florida rally in February 2016. “Obamacare is a total and complete disaster. It’s going to be gone. We’re going to come up with a great health care plan, whether it’s health care savings accounts, we have a lot of different things.”

“We will terminate Obamacare and replace it, believe me, with something good,” he said in May 2016 in California. “Believe me. Repeal and replace Obamacare.”

“ObamaCare is imploding,” Trump tweeted in March. “It is a disaster and 2017 will be the worst year yet, by far! Republicans will come together and save the day.”

Trump’s calculation – and he placed a VERY big bet on this – was that he could win the GOP nod (and get elected president) by being the polar opposite of Obama on, well, pretty much everything. That started with his condemnation of Obamacare but has continued with his decision to de-certify the Iran nuclear deal, his pullout from the Paris climate accords, his support for the Keystone XL pipeline, his regulatory rollbacks, his plan to end DACA and lots (and lots) of other policy decision from this administration in its first nine months.

It’s as though Trump is wearing a bracelet that with the initials WWOD (“What Would Obama Do”) – and then does the exact opposite. The unraveling of Obamacare then, which is what Trump is on his way to doing, is a stand-in for the broader unraveling of the Obama legacy.

The problem with that approach, of course, is that being against what the last guy did isn’t a proactive set of policy solutions. Unlike in a campaign – in which saying, essentially, “I’ll do the opposite of what the last guy did” – where running against something often works better than running for something, governing is a very different animal.

Remember that Trump was elected to bring about needed change in Washington. Getting rid of things Obama did is only part of that promise. Putting in conservative solutions that the GOP believes will work better is the second half – and has very little to do with Obama and the actions he took in office.

Trump will be cheered by conservatives in and outside of Washington for his moves to force the failure of Obamacare. But, if Republicans in Congress can’t find a way to pass some sort of meaningful replacement plan, that joy may soon turn to ashes in their mouths.

CORRECTION: Donald Trump’s decision to cut subsidies to insurance companies for lower-income Americans was not an executive order.