If they squint hard enough, Republicans looking at President Trump can almost see George W. Bush.

Government spending and the debt are soaring, provoking grumblings about fiscal recklessness. Taxes were slashed at the expense of balanced budgets. Thousands of additional troops have been deployed into war zones half a world away. And with the exception of some highly specific tariffs, international trade remains free and unfettered.

For all the ways Mr. Trump has defied and flouted the norms of his office, many policies that he has approved are downright ordinary by the standards of modern Republican administrations. It is a far cry from the mold-shattering approach he talked about before he became president, insisting he would punish China for “ripping us off,” pull out of Afghanistan because “we waste billions there” and slash the debt because it was “bad for the country.”

Many Republicans say that what has unfolded so far is not the Trump administration they were expecting.