Poll: Trump lead shrinks in Iowa, N.H.

Donald Trump still leads polls in the states that open the 2016 Republican presidential contest -- Iowa and New Hampshire -- but the margins have shrunk some in the past month, according to new surveys.

Trump has 24% in Iowa while another "outsider" candidate, retired neurosurgeon Ben Carson, is second at 19%, according to the NBC News/Wall Street Journal/Marist poll.

"A month ago, Trump's lead over Carson in Iowa was seven points in the same poll, 29% to 22%," NBC News reported.

A third candidate with no previous elected experience, businesswoman Carly Fiorina, is third in Iowa with 8%, according to the poll, followed by Jeb Bush (7%), Ted Cruz (6%), Marco Rubio (6%), and Bobby Jindal (6%).

The Iowa caucuses open the 2016 election season next February.

In New Hampshire, Trump leads Fiorina 21%-16%, followed by Bush (11%), Rubio (10%), and Carson (10%).

A month ago, according to the same poll, Trump led then-second place candidate John Kasich by 16 points.

The Iowa and New Hampshire polls were conducted in the wake of the Sept. 16 Republican debate and the withdrawal of Wisconsin Gov. Scott Walker from the GOP presidential race.