Democrats are trying to tie Republicans to other controversies involving Trump.
New York Rep. Jerrold Nadler introduced a resolution of inquiry in February that would ask the Justice Department to investigate Trump's potential conflicts of interest, ethics violations and ties to Russia.
Nadler sought a full floor vote if the House Judiciary Committee didn't act. But his resolution went nowhere either in committee or on the floor.
Republican strategist Michael Steel, who worked for former Speaker John A. Boehner, said it's unlikely that the Democrats can score points on Trump's tax returns.
"It's clearly not an issue that hurt the president in the general election," said Steel, who also worked for former Florida Gov. Jeb Bush's presidential campaign where he ran against Trump.
"It's not a high-priority issue for the American people," he said. "And it doesn't help Washington Democrats appeal to the swing voters they would need in the midterms."
Republicans used similar tactics when they were in the minority, Steel said. But Republicans, he said, also pushed for procedural votes that were able to split Democrats on issues like immigration and guns.
"The powers of the minority in the House are very limited, which makes it even more important to do it in a smart way," he said.
Manley isn't opposed to using procedural votes against Republicans now that they're in the majority.
"When you're in minority in House it's difficult to follow through," he said. "But it gives a great message," he said.