Today, the United States Senate rejected a measure that would have made it more difficult for criminals and the mentally ill to purchase a gun. This bill – a bipartisan compromise crafted by Senators Pat Toomey (R-PA) and Joe Manchin (D-WV) – would have expanded existing background checks to gun shows and online sales, thereby closing an easily exploited loophole used by criminals to purchase firearms without having to pass a background check. Importantly, this bill closed the loophole in a way that did not infringe on law-abiding gun owners' right to bear arms.

The case for expanded background checks was made most clearly by Vice President Joe Biden in his recent comment to Hearst newspapers that al-Qaida is telling its followers to exploit the "gun-show loophole" to buy semi-automatic weapons here in the U.S. Our gun violence prevention laws are so weak in this country that even known terrorists can bypass background checks and buy a gun here.

I am outraged that the Senate failed to pass this commonsense legislation. With more than 90% of Americans supporting background checks according to Gallup polling, it is simply unfathomable that this obvious legislation did not garner the needed votes to pass the Senate and move onto the House of Representatives. The victims of Newtown – and the over 3,000 people who have been killed by gun violence since then – deserve better than that.

The bottom line is that if you cannot pass a background check, you should not own a gun. I am bitterly disappointed in this Congress' inability to pass commonsense gun violence prevention legislation, but I remain determined to work with my colleagues to ensure safer schools and communities for our children.