REP. TOM PRICE (R-Ga.), President Trump’s pick to run the Department of Health and Human Services, is a walking, talking example of the ways in which congressional ethics requirements are too lax.

While in Congress, Mr. Price traded hundreds of thousands of dollars in health-care-related stocks. In at least one case, a trade coincided with legislative efforts from Mr. Price that, if successful, would have affected the company he owned a piece of. In another case, the congressman was one of a select group of investors offered a private stock-purchasing deal in an Australian biotechnology company. Making the picture only more unattractive, Mr. Price apparently learned about the company from another House member, Chris Collins (R-N.Y.), who was on the firm’s board.

When questioned about this unsavory history at a hearing before the Senate Finance Committee on Tuesday, Mr. Price mostly restated that he followed applicable House ethics rules and disclosed the purchase and sale of health-care-related stocks while he was a leading figure in crafting health-care policy in Congress. This response only underlines the point that congressional ethics rules are inadequate and that Mr. Price should have known better.

Aside from pointing out that he did not violate House standards, Mr. Price has also claimed that he relinquished management of his stock portfolio, leaving trading decisions to a professional broker. Yet Mr. Price did not create a truly blind trust; he eventually learned what his financial interests were. Mr. Price also admits he pursued the private stock deal in Mr. Collins’s company of his own volition.

One does not have to presume any corrupt intent on Mr. Price’s part to find these facts unsettling. As with other government officials, Americans should have confidence that those making policy on their behalf are doing so based on principles and not the potential for personal gain. The simple fact of conflicts of interest corrodes that faith. Strong rules should be in place to prevent such erosion of trust. Obviously those rules still do not exist, even after the last round of congressional ethics reforms. The Price hearings show that lawmakers should reconsider proposals they previously rejected that would have restricted the sorts of investments they can make.

Meanwhile, on the substance of health-care policy, Mr. Price offered his usual vague assurances that Republicans could solve all manner of health-care challenges. But he provided few plausible details to suggest the new administration could make good on rhetoric suggesting it can lower deductibles, cut premiums, expand patient choice and ensure universal access to quality care — which, barring an increase in federal spending, would be the health-policy equivalent of alchemy.

If confirmed, Mr. Price will lead a $1 trillion agency responsible for the well-being of millions of Americans, and he will play a key role in shaping a health-care system that Mr. Trump is already rushing headlong to upend. He should have better answers than the ones he offered during his hearings.