我看可以。因为按照美国土安全部的明文规定：

U.S. citizens entering the United States at sea or land ports of entry are required to have documents that comply with the Western Hemisphere Travel Initiative (WHTI), most commonly a U.S. passport, a passport card, a trusted traveler card such as NEXUS, SENTRI or FAST, or an enhanced driver's license。而WHTI要求的旅行证件只要能够证明国籍身份即可：The Western Hemisphere Travel Initiative (WHTI) requires U.S. and Canadian travelers to present a passport or other document that denotes identity and citizenship when entering the U.S. It is a result of the Intelligence Reform and Terrorism Prevention Act of 2004 (IRTPA).不过还是建议你给小孩子办个护照，我的小儿9个月大时就办了护照。