With Vice President Joe Biden presiding over the Senate, an amendment to expand background checks on gun purchases failed to pass through the body, falling by a mostly partisan vote of 54-46.

In a subsequent statement at the White House, President Barack Obama lambasted the Senate in what he called a "shameful day in Washington."

Sixty votes were needed to pass the legislation through the Senate. Four Democrats voted no on the measure. All but four Republicans voted no.

With prospects already looking bleak, gun-control supporters lost two potential key votes earlier Wednesday, as Sens. Kelly Ayotte (R-N.H.) and Heidi Heitkamp (D-N.D.) said they would oppose the measure, which was introduced by Sens. Pat Toomey (R-Pa.) and Joe Manchin (D-W.Va.).

In addition to Heitkamp, the other three Democrats voting against the measure were Sens. Mark Begich (D-Alaska), Max Baucus (D-Mont.), and Mark Pryor (D-Ark.).

Check out our previous updates throughout the day.