New York's attorney general, Andrew Cuomo, has said he is running for New York governor, a post his father once held.
Mr Cuomo, 52, has gained popularity for bringing a number of high profile corruption cases against New Yorkers.
Correspondents say he is virtually unopposed for the Democrat nomination.
Governor David Paterson bowed out of the race in February amid a scandal involving one of his aides.
"New York state is upside down and backwards - high taxes and low performance," Mr Cuomo said in a video announcing his candidature.
"The New York state government was at one time a national model. Now, unfortunately, it is a national disgrace".