The U.S. Senate rejects a bipartisan plan to expand background checks for gun buyers, dealing a sharp blow to President Barack Obama's campaign to curb gun violence after the Newtown school massacre.

At the White House, President Barack Obama spoke surrounded by victims of gun violence.

(SOUNDBITE) (English) UNITED STATES PRESIDENT BARACK OBAMA SAYING:

"So all in all this was a pretty shameful day for Washington."

With polls showing that a wide majority of Americans supporting expanded background checks for gun buyers, Obama said the resistance was political.

(SOUNDBITE) (English) UNITED STATES PRESIDENT BARACK OBAMA SAYING:

"There were no coherent arguments as to why we wouldn't do this. It came down to politics. the worry that that vocal minority of gun owners would come after them in future elections."

Obama said the fight is not over -- he called it round one -- and called on supporters of gun control to put pressure on lawmakers at the bal