Democratic presidential candidate and former U.S. Vice President Joe Biden speaks during a forum held by gun safety organizations the Giffords group and March For Our Lives in Las Vegas, Nevada, October 2, 2019.

Former Vice President Joe Biden's grip on Democratic presidential primary polling has loosened in recent weeks as surveys show tight races in key early nominating contests.

Since he entered the jammed race to challenge President Donald Trump in April, Biden has enjoyed an edge in early surveys nationwide and in the pivotal states of Iowa, New Hampshire, Nevada and South Carolina. His standing as the clear front-runner has dissolved with a little over three months remaining until the first-in-the-nation Iowa caucus, according to polling averages.

Sen. Elizabeth Warren, D-Mass., has steadily climbed in national surveys to a point where she sits fewer than 5 percentage points behind Biden in a RealClearPolitics average. Meanwhile, polls show Biden jockeying for position with Warren, Sen. Bernie Sanders, I-Vt., and South Bend, Indiana, Mayor Pete Buttigieg in the early voting states.

Even as he faces increased competition in other key states, polls have consistently found a massive lead for Biden in the fourth Democratic nominating state of South Carolina.

While national surveys help to gauge candidates' overall standing, state polls provide a better picture of voter sentiment in places where voters will actually decide on candidates in the coming months. The dynamics of the race could change significantly between now and early February, when the Democratic nominating contests will start.

Here's where the polling averages stand currently at the national level and in the first four nominating states. The top 10 candidates in the primary field of 19 are listed.

Other candidates at least tying for a top 10 spot in a national or early state polling average are Sen. Kamala Harris, D-Calif.; entrepreneur Andrew Yang; Sen. Amy Klobuchar, D-Minn.; Sen. Cory Booker, D-N.J.; activist Tom Steyer; Rep. Tulsi Gabbard, D-Hawaii; former Rep. Beto O'Rourke; former Housing and Urban Development Secretary Julian Castro, and author Marianne Williamson.

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