Few in Congress have been more involved in the gun violence debate following the Feb. 14 Parkland, Fla., massacre than Sen. Marco Rubio, R-Fla.

Yet, despite his efforts, Rubio has also become the preferred punching bag for both sides, particularly the one that favors increased restrictive measures on gun owners. Gun controllers have accused the senator of putting a “price tag” on student lives, while others claim he has “offered nothing.”