Passage of the amendment from House Judiciary Committee Chairman Lamar Smith (R-Texas) seemed to be somewhat in doubt because the several controversies surrounding the bill. But passage may indicate the bill will be approved by the House later tonight.

Several members of both parties argued Wednesday that the bill is unconstitutional because it would seem to go against language that protects inventors and shift the U.S. to a "first to file" system. Some said this would force inventors to win a race to the patent office in order to hold patent rights.

"The bill would permit the Patent and Trademark Office to award a patent to the first person who can win a race to the patent office regardless of who is the actual inventor," House Judiciary Committee Ranking Member John Conyers (D-Mich.) said Wednesday. "This is patently unfair to inventors."

Democrats also argued that the bill would not ensure that fees collected by the U.S. Patent and Trademark Office are kept in that agency and used to fund patent examiners.

With approval of the manager's amendment, the House is expected to consider 14 other amendments to the bill Thursday and hold votes on them later in the day.