House Speaker Paul D. Ryan said Tuesday that the rollout of President Trump’s extreme vetting executive order was “regrettable,” but said the new policy is not only legal, but the right thing to do to try to head off a future terrorist attack. He said he’s talked with new Homeland Security Secretary John F. Kelly to make sure the policy is carried out better, particularly when it comes to green card holders who were getting snared in the early going. But he said the House, in a bipartisan fashion, voted to back a pause in the refugee program in the...