Congress can seek eight years of President Trump's tax records, according to a federal appeals court ruling on Wednesday.Why it matters: It's a major setback for Trump, who's tried to block every attempt to make his tax returns public and plans to take the case to the U.S. Supreme Court.What they're saying: Trump's lawyer Jay Sekulow confirmed after the 8-3 vote by the U.S. Court of Appeals for the D.C. Circuit that rejected the president's request to "rehear arguments that the subpoena to Mazars LLP was illegitimate" that his legal team would appeal to the Supreme Court, per Reuters.Sekulow said after Trump lost his New York tax returns fight that the issue "goes to the heart of our republic," per Bloomberg. "The constitutional issues are significant," he said.Read the court's decision: Go deeper: Trump intends to take tax return fight to Supreme Court The fight for Trump's taxesEditor's note: This article has been updated with new details throughout.