House Republicans are planning to include several of President Trump’s campaign promises in the first draft of the bill, which they hope to release soon.It was easy to miss, but last weekend President Trump floated a fundamental rewrite of the American tax code. In a social media post, and again in remarks to reporters, Mr. Trump suggested the United States could stop taxing income under $200,000 and instead rely on revenue from his extensive tariffs. “It’ll take a little while before we do that, but we’re going to be cutting taxes, and it’s possible we’ll do a complete tax cut,”...