WATCH: LBJ's Daughters Back Marriage Equality, Think He Would Have

It's impossible to say how the late president Lyndon B. Johnson would feel about marriage equality -- but his daughters suspect he would be for it, they told Katie Couric in a recent interview for Yahoo! News.

"I think my father felt very strongly that when there was bigotry anywhere, prejudice anywhere, all of us lose out," said Luci Baines Johnson. "Because it's just one more expression of hate."

Added her sister, Lynda Bird Johnson Robb: "It's hard to project what Daddy would have thought about that because that wasn't an issue that had come upon the States at that time. But I know he really wanted everybody to be able to live up to the best that God gave them."

After Lyndon Johnson, a Texan, became president upon the assassination of John F. Kennedy, he surprised his fellow Southerners and many others by wholeheartedly advocating for civil rights for African-Americans. This year marks the 50th anniversary of the Civil Rights Act of 1964, which he signed into law.

Both daughters see marriage equality as a matter of civil rights, and they support it. "I certainly think that, if God made you a homosexual, that you should have love and affection with somebody," Robb told Couric. "And I would not want to deny anybody that opportunity to be happy."

"It's a great civil rights concern of our day," Johnson added.

Watch a clip from the interview below, and find more of the Johnson daughters' comments on their father's legacy here.