Story highlights Hillary Clinton has the most support among Democratic caucus-goers in Iowa, according to a new poll

Vermont Sen. Bernie Sanders, however, shows some strength

Washington (CNN) The first CNN/ORC poll of likely Democratic caucus-goers in Iowa finds Hillary Clinton firmly in the lead in the state that kicks off the nation's nominating contests, holding a 50% to 31% lead over upstart Vermont Senator Bernie Sanders. Vice President Joe Biden, who has yet to decide whether to make a run for presidency, lands in third place with 12%, with the rest of the field at 1% or less.

The slightly-tighter-than-national race reflects two broad divides among Iowa's Democratic voters: a gender gap and an ideological split. Among women, Clinton tops Sanders by more than 30 points, 58% to 26%. Among men, the two are even: 38% back Clinton, 37% Sanders. Likewise, among the party's moderates, 57% back Clinton, 21% Sanders, while liberals split 46% for Clinton to 41% for Sanders. And liberals are most apt to say they are firm in their choice: Fully 42% say they've definitely decided whom to support, compared with 30% overall.

All told, nearly half of Iowa's likely Democratic caucus-goers say they've either made up their minds about the race or are leaning toward a candidate (46%), and among that group, Clinton stands at 53%. Sanders jumps to 41% among those who have made up their minds and despite not having made up his own mind about running, Biden has 5%. Former Maryland governor Martin O'Malley rounds out the list at 1%.

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