Obama´s lead over Clinton in national poll shrinks to zero

These results "suggest that Democratic voters are -- for the moment at least -- divided right down the middle as to which candidate they most want to represent their party in November's general election," the poll says.

The polling body also found in the latest survey conducted among national registered voters from April 22 to 26 that Clinton maintains her advantage over Republican presumptive presidential candidate, Arizona Senator John McCain, in the general election preferences at 47 percent to 44 percent.

Obama and McCain are tied at 45 percent each, it added.

U.S. Senator and democratic presidential hopeful Barack Obama  waves to supporters as he is introduced during a campaign stop  in Kokomo, Indiana April 25, 2008.

Editor:Zhao Yan