ON SOME points President-elect Donald Trump has been consistent. One of those is opposition to the 2010 Dodd-Frank financial regulation law, which as a candidate he repeatedly blamed for crippling the financial sector and stifling economic growth. Now he and his fellow Republicans, who control Congress, are in a position to make good on his promise to either scrap it or substantially revise it. What would they put in its place?

Any such discussion should begin by acknowledging that the major banks are far more stable today than they were before the panic of 2008, and that tighter regulation under Dodd-Frank is one reason why. Since the crisis, the top 33 institutions have added more than $700 billion in high-quality capital, according to the Federal Reserve. The Fed’s June 2016 “stress test” (required by Dodd-Frank) determined that the big banks could withstand a severe global recession that raised U.S. unemployment five percentage points — with no taxpayer bailout.

It would be the height of folly, not to mention a contradiction of Mr. Trump’s purported concern for working-class Americans, if his administration were to enable the reversal of these achievements. Dodd-Frank is a hideously complex law, and it imposes significant compliance costs on smaller financial institutions not responsible for the 2008 panic, as its critics say. However, if it’s going to be streamlined and simplified, the paramount goal should be to reinforce, not weaken, strong capital requirements for banks.

There is no shortage of proposals for doing this. Some, such as the Republican platform’s odd call for a restoration of the Depression-era Glass-Steagall Act, would enjoy bipartisan support, even if Glass-Steagall’s emphasis on separating commercial from investment banking is not entirely relevant to today’s financial stability challenges. The Federal Reserve Bank of Minneapolis, under President Neel Kashkari, has unveiled a plan that would require bank holding companies with more than $250 billion in assets to hold as much as 38 percent equity capital — a rule that could constitute a de facto bank breakup.

However, the main Republican legislative plan is House Financial Services Chairman Jeb Hensarling’s (Tex.) bill, which would all but dismantle Dodd-Frank. Its least attractive proposal is one that would, in the name of ending bailouts, further constrain the Fed’s ability to act as a lender of last resort to troubled but salvageable financial firms. Rather than stabilizing the system, this could destabilize it by deterring needed crisis borrowing. More promising is Mr. Hensarling’s idea to offer regulatory relief to banks that hold at least 10 percent capital as a buffer against losses, which could be stabilizing, as long as the capital is defined as real equity, and not the “risk-weighted” variety that regulators too often accepted in the past. 

Meanwhile, except for Mr. Kashkari, who wants to put a tax on hedge funds and finance companies, depending on the risk they pose to the wider system, no one is talking much about the “shadow banking” sector. Yet it must be addressed, lest systemically risky activity simply migrates there from more tightly regulated portions of Wall Street. During the campaign, only Hillary Clinton flagged that important issue.