IN THE AFTERMATH of the debacle over the Republican effort to repeal and replace Obamacare, President Donald Trump can learn a valuable lesson that will serve him well in the next battle over tax reform and other issues.

The president was elected largely on the force of his strong personality and vague promises to fix things that are a disaster, a favorite word of his.

Personality is not policy. Leaders who lead by personality also can die by personality, which is what happened in the House last week, when the president’s threats and arm-twisting failed to deliver enough votes. The strategy, if one can call it that, now appears to be to allow Obamacare to collapse under the weight of rapidly rising premiums and deductibles, withdrawal of insurance companies from the exchanges and limited access to physicians of one’s own choosing.

The president’s thinking appears to be that, prior to next year’s congressional elections, Democrats will come crawling to him and beg for political relief. I wouldn’t count on that.

Politicians regularly campaign on promises to change Washington or in Trump’s vernacular, to “drain the swamp.” No one can really change Washington. More politicians are changed by Washington than change its political culture. As for draining the swamp, that would be fine, as long as the swamp only contained water, but the swamp contains politicians, lobbyists, lawyers and numerous interest groups one might call swamp people. These people are happy with the status quo because it gives them access to government and a sense of power, not to mention vast sums of money for persuading members of Congress to include, or exclude, items in legislation that appeal to their wealthy clients.

Before embarking on tax reform, the president might first consider a campaign to expose the numerous ways Washington wastes taxpayer money. The federal government collected $422 billion in the first two months of fiscal 2017, according to the Washington Free Beacon. The prior year also saw record amounts in tax revenue. Why does the government never have enough of our money? Why doesn’t the government ever ask if we have enough? It’s not just income taxes. There are taxes and fees on everything, from airline tickets to fishing and dog licenses. The website theeconomiccollapseblog.com lists 97 of them.

Trump should read the tax reform speech Ronald Reagan delivered from the Oval Office May 28, 1985. While Reagan had an undeniably strong personality, this speech was full of policy specifics and led to the Tax Reform Act of 1986, the last time the tax code was reformed.

Here is part of what Reagan said “For the sake of fairness, simplicity and growth, we must radically change the structure of a tax system that still treats our earnings as the personal property of the Internal Revenue Service; radically change a system that still treats people’s earnings, similar incomes, much differently regarding the tax that they pay; and, yes, radically change a system that still causes some to invest their money, not to make a better mousetrap but simply to avoid a tax trap.

“Over the course of this century, our tax system has been modified dozens of times and in hundreds of ways, yet most of those changes didn’t improve the system. They made it more like Washington itself — complicated, unfair, cluttered with gobbledygook and loopholes designed for those with the power and influence to hire high-priced legal and tax advisers.”

There were two keys to getting tax reform passed then: An avalanche of letters and phone calls to Congress from people of all political stripes, and Reagan’s pledge to work with Democrats on a reasonable bill that would give Democrats partial credit.

Trump should follow Reagan’s strategy, which was more policy than personality.