[cnn-photo-caption image= http://i.l.cnn.net/cnn/2008/images/02/01/art.kennedyad.cnn.jpg caption="Robert Kennedy Jr., stars in a new Clinton ad."](CNN) - Days after three influential Kennedys came out in support of Barack Obama, Hillary Clinton released an ad featuring her own Kennedy clan supporter: Robert F. Kennedy's son Robert.
The environmental activist and attorney publicly endorsed the New York senator’s White House bid late last year.
This presidential campaign cycle has seen a split in the Kennedy family, many of whom generally avoid weighing in on political contests. Massachusetts Sen. Ted Kennedy, Rhode Island Rep. Patrick Kennedy and former First Daughter Caroline Kennedy all endorsed Obama at a campaign rally on Monday. Caroline has since appeared in an Obama campaign commercial, and Sen. Kennedy has begun stumping for the Illinois senator in key Western states that head to the polls February 5, Super Tuesday.
In the new 30-second Clinton ad, Robert Kennedy compares the New York senator to his father, who also served as a New York senator after a stint as attorney general in the administration of his brother John F. Kennedy.
"My father tried to be a voice for the most alienated and disenfranchised members of our society, from Appalachia to the migrant farm workers," Kennedy says. "Today Hillary Clinton is the champion for the voiceless in our society."
A Clinton ad also features the grandson of the late Cesar Chavez, a labor activist and former leader of the United Farm workers. "Hillary knows how to solve our problems, to get things done," says Cesar L. Chavez.
On the trail, Obama has used the slogan “Si Se Puede” – generally translated as “Yes We Can” – popularized by the late Chavez, a revered figure within the Latino community.
–-CNN Associate Producer Rachel Streitfeld