The Civil Rights Act must have been before your time, Charlie.  But it wasn't before mine.  Here are the "facts":

"The Civil Rights Act -- which is best known for barring discrimination in public accommodations -- passed the House on Feb. 10, 1964 by a margin of 290-130. When broken down by party, 61 percent of Democratic lawmakers voted for the bill (152 yeas and 96 nays), and a full 80 percent of the Republican caucus supported it (138 yeas and 34 nays).

When the Senate passed the measure on June 19, 1964, -- nine days after supporters mustered enough votes to end the longest filibuster in Senate history -- the margin was 73-27. Better than two-thirds of Senate Democrats supported the measure on final passage (46 yeas, 21 nays), but an even stronger 82 percent of Republicans supported it (27 yeas, 6 nays)."

In the House, Democrats were nearly 2/3 of the yes votes, but also 2/3 of the no votes.
The filibustering Senators were Democrats.