Supreme Court Justice Scalia -- Thousands Gather To Pay Respects

Justice Scalia was honored in Washington D.C. Saturday ... with thousands gathering to mourn the loss of the heart and soul of the conservative justices.

Scalia's son Paul delivered Mass at the Basilica of the National Shrine of the Immaculate Conception in D.C. Every current member of the Supreme Court sat in the front row and Justice Clarence Thomas participated in the service.

President Obama was not in attendance -- something he's taking heavy criticism from Republican for -- however, he and first lady Michelle paid their respects on Friday at the Supreme Court Building.

Donald Trump was quick to attack Obama for the no-show, tweeting, "I wonder if President Obama would have attended the funeral of Justice Scalia if it were held in a Mosque? Very sad that he did not go!"

As TMZ reported ... Scalia died in his sleep last week on a hunting trip in Texas. He was 79-years-old.