The candidacy of Barack Obama has received a significant boost with the endorsement of two members of one of America’s most influential political dynasties.

Caroline Kennedy, the daughter of former President John F Kennedy, wrote an highly personal opinion piece in the New York Times yesterday comparing Senator Obama to her father and praising him as an inspirational candidate.

Later today Senator Edward Kennedy, brother of the former President and assassinted Presidential candidate Bobby Kennedy, will appear at a rally with Senator Obama and publicly back his run for the Democratic nomination.

The support of the Kennedy family is highly significant at this key moment in the electoral cycle.

Next week 22 states will pick a Democratic candidate, representing more than 50% of the overall number of delegates to the party’s nominating convention.

On Saturday Mr Obama won a decisive victory in the South Carolina primary over Senator Hillary Clinton.

The two frontrunners in the race for the Democratic nomination for President have now won two states each.

In her piece for the New York Times, entitled A President Like My Father, Ms Kennedy wrote:

“I want a president who understands that his responsibility is to articulate a vision and encourage others to achieve it; who holds himself, and those around him, to the highest ethical standards; who appeals to the hopes of those who still believe in the American Dream, and those around the world who still believe in the American ideal; and who can lift our spirits, and make us believe again that our country needs every one of us to get involved.

“I have never had a President who inspired me the way people tell me that my father inspired them. But for the first time, I believe I have found the man who could be that president – not just for me, but for a new generation of Americans.”