WASHINGTON — In his news conference on Wednesday, President-elect Donald J. Trump claimed that the American public did not care that he had not released his tax returns, as has been routine for every presidential nominee since Watergate. He could not be more wrong. When I asked users on Twitter, the president-elect’s favored megaphone, to retweet if they cared about Mr. Trump’s tax returns, within hours more than 79,000 people responded.

The reason is simple. Without these returns, Americans cannot know whether he is using the presidency to enrich himself and his family. Americans won’t know whether a policy he proposes primarily benefits steelworkers in Pennsylvania or lines his own pocket.

They will also be unable to tell whether Mr. Trump is telling the truth when he claims to have no connections to Russia, contradicting public evidence and statements by his own son. His stated excuse about being under audit doesn’t pass the smell test. Previous presidents and nominees have released their returns under the same circumstances.

That’s why I and dozens of congressional colleagues have introduced legislation to force future presidential nominees and presidents to release their tax returns. As representatives of the people, if we can’t trust the executive branch to act ethically, we must force it to do so.