One example was the president's talk on repealing and replacing Obamacare, which the Maryland Democrat said was not realistic due to the lack of clarity around how Trump plans to get it done.
"We still have no bill from President Trump. We have no bill from the Republicans" that is aimed at fixing the sweeping health-care law, Hoyer said. "So I don't think we got much realistic talk. We got some happy talk last night."
The congressman said Trump's mission to rid the Affordable Care Act of its individual mandate, which requires Americans to buy coverage, raises questions about how the president plans to fund the replacement.
Hoyer argued that the mandate "was included so that insurance companies would have more clients, spread the risk, which is what insurance is all about, and therefore make it affordable."
"If you eliminate [the mandate], how are you going to pay for it?" the congressman asked. "How are you going to have insurance companies in the market?"
Rebuilding infrastructure, another key policy touted by Trump in his speech, has also created stark disagreement in Congress over how Trump's trillion-dollar initiative will be funded, Hoyer said.
But across-the-aisle agreement is just as important as intra-party agreement, which Hoyer said can be a challenge among Republicans.
"They have deep division," he said. "So yes, they have the majority in terms of the numbers, but they don't have agreement within their party. They don't have a consensus, which you need to have."
Hoyer, the second-ranking Democrat in the House, spoke in an interview on "Squawk Box" the morning after Trump's address to a joint session of Congress. In a wide-ranging speech, the president outlined some of his key policy initiatives.