At issue is whether changing the U.S. system from a "first-to-invent" system to a "first-inventor-to-file" system violates Article 1, Section 8, Clause 8 of the Constitution. That clause grants Congress the power to "promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries."

Supporters of the bill, called the America Invents Act, argue that moving to a "first-inventor-to-file" system is in line with the Constitution and also has the benefit of moving the U.S. closer to the "first-to-file" system that most of the rest of the world uses.

"The bill's inclusion of a move to a first-inventor-to-file system is absolutely consistent with the Constitution's requirement that patents be awarded to the inventor," House Judiciary Committee Chairman Lamar Smith (R-Texas) argued.

But several Republicans and Democrats objected, arguing that the proposed change would put in place a new requirement that inventors file for their patents first in order to be awarded rights that they should already have under the Constitution by having invented a novel product or process.

"Supporters of this bill say it's an attempt to modernize our patent system," Rep. Marcy Kaptur (D-Ohio) said. "What they really mean is that this bill Europeanizes our patent system by granting the rights to an invention to whoever wins the race to the patent office."

She was joined by Rep. Jim SensenbrennerJames SensenbrennerWhy Congress needs to reform structured settlements Congress should act to stop states from battling over online sales taxes Congress should prioritize small farmers and taxpayers over Big Ag MORE (R-Wis.), a senior member of the Judiciary Committee.

"Unlike what my friend from Texas Mr. Smith has said, this bill is unconstitutional, and voting for this bill will violate one's oath of office," he said. "A first to invent and first to file provision is unconstitutional because it adds a layer of compliance in winning a race to the patent office for someone who already has that right."

Kaptur and Sensenbrenner were joined in opposition to the bill by Republican Reps. Lee Terry (Neb.), Dana Rohrabacher (Calif.), and Scott GarrettScott GarrettHeitkamp breaks with Dems on regulations Business groups silent on Trump's Ex-Im nominee Trump should work with Congress to kill the Export-Import Bank MORE (NJ). Garrett argued that the bill is unconstitutional because it gives the right to award the patent to a government agency, and ignores language in the Constitution saying Congress must help secure rights to authors and inventors.

But Smith was joined in support of the bill by members of both parties. Rep. Jerrold Nadler (D-NY) said the bill still requires patent seekers to be inventors, and argued that the Constitution is not explicit on how Congress must ensure patent rights. Rep. Bob GoodlatteBob GoodlatteTech giants urge Congress to revise foreign surveillance law Top Dem calls for investigation into Sessions House votes to expand death penalty for police killings MORE (R-Va.) agreed.

"This is first inventor to file," Goodlatte said. "You must be a bona fide inventor to qualify for this." Both Nadler and Goodlatte are on the Judiciary Committee.

After debate on the constitutionality of the bill, members began general debate on it shortly before 8 p.m., and was expected to begin considering amendments to the bill Wednesday night.