WASHINGTON — Almost a third of likely Democratic caucus goers in Iowa preferred former Vice President Joe Biden in the Des Moines Register/CNN/Mediacom Iowa Poll that showed U.S. Sen. Cory Booker with some distance to make up.

Biden polled 32 percent, followed by U.S. Sen. Bernie Sanders, I-Vt., with 19 percent and Rep. Beto O’Rourke, D-Texas, with 11 percent.

Booker, D-N.J., was sixth with 4 percent, behind also U.S. Sens. Elizabeth Warren, D-Mass. (8 percent) and Kamala Harris, D-Calif. (5 percent).

U.S. Sen. Amy Klobuchar, D-Minn., and Michael Bloomberg, the former Republican mayor of New York City who returned to the Democratic Party, each had 3 percent.

Booker told NJ Advance Media that he would “consider running for president" in 2020 and would "take some time during this holiday season to sit with family and close friends and advisers to give it a really good consideration.”

The Iowa caucuses, the first contest of the 2020 presidential primary season, are set for Feb. 3, 14 months from now.

Booker has plenty of time to improve his standing, however. Almost 4 in 10 likely caucus goers couldn’t express an opinion about him. Among who did, he was viewed favorably by 49 percent and unfavorably by just 12 percent.

He visited Iowa jn October, when he spoke at the state Democratic Party’s annual gala and then participated in a get-out-the-vote drive across the state.

Booker also has made two trips to New Hampshire, site of the first Democratic primary.

The poll of 455 likely Democratic caucus goers was conducted Dec. 10-13 and had a margin of error of 4.6 percentage points.

Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.