The implosion of the Republican health-care bill shows the limits of what one party alone can do in Washington. Tax reform will be even trickier, since it touches a larger fraction of the economy and threatens more powerful vested interests. The only hope for seriously revamping America’s inefficient business-tax system to unlock stronger economic growth is a bipartisan approach, but it will require a course correction by President Trump. Here are five important steps to building a sensible tax reform:

• Commit to revenue neutrality and distributional neutrality, as in the 1986 tax reform. In other words, a bipartisan plan would focus on making the tax system more efficient, without cutting the revenue raised or shifting the burden in any direction. This would not require a change in rhetoric. House Speaker Paul Ryan has already said tax reform should be revenue-neutral, and Treasury Secretary Steven Mnuchin has said that there will be “no absolute tax cut for the upper class.”

Any specific legislation should be judged against these benchmarks by the nonpartisan analysts at the Joint Committee on Taxation, a group that incidentally now uses dynamic scoring in assessing major tax changes. But the frameworks put out last year by the Trump campaign and House Republicans do not pass the test. They would add trillions of dollars to the deficit while providing, respectively, 50.8% and 99.6% of their benefits to the top 1%, according to the Tax Policy Center.

• Focus on business taxes only. This is where the largest economic gains from tax reform can be found. In part that’s because companies can and do move across borders in search of lower taxes, while individuals are much less likely to do so.

For a reformed system to work, all large companies should have to file under the corporate tax code, as President George W. Bush’s tax-reform commission proposed. Small businesses should have their rates left alone but could be helped in other ways—for instance, with more-generous tax breaks for research or employer benefits.