CNN and The Des Moines Register to release 2020 Iowa caucus poll Saturday

The results of the CNN/Des Moines Register/Mediacom poll will be released at 8 p.m. ET on Saturday.

A clear leader has yet to emerge among the large field of Democratic contenders in the first-in-the-nation caucus state.

Massachusetts Sen. Elizabeth Warren has been challenging former Vice President Joe Biden's dominance in the race for the Democratic nomination, polling at 22% to Biden's 20% in the latest CNN/Des Moines Register/Mediacom poll that was released in September. In that same poll, Vermont Sen. Bernie Sanders' support dipped to 11%.

Since then, the candidates have had an opportunity to try and impress Iowans in the fourth Democratic presidential debate in October, hosted by CNN and The New York Times, and during the biggest Democratic event of the year in Iowa -- the Liberty and Justice Celebration.

South Bend, Indiana, Mayor Pete Buttigieg, who previously told CNN that "Iowa is central," has spent most of his time focused on Iowa and staffing up in the state.

In the past two weeks, three polls have shown Buttigieg joining the top tier of Democratic presidential candidates in Iowa.

Buttigieg was up 14 percentage points since August, according to a new Monmouth University poll of likely caucusgoers out earlier this week.

In a Siena College/New York Times Upshot poll released November 1, Warren received 22% support among likely Democratic caucusgoers, followed by 19% for Sanders, 18% for Buttigieg, and 17% for Biden.

A Quinnipiac poll from last week mirrored those results, with Warren at 20%, Buttigieg at 19%, Sanders at 17%, and Biden at 15%.

Since the last CNN/Des Moines Register/Mediacom poll, there has been some shakeup to the Democratic field.

Former Texas Rep. Beto O'Rourke dropped out of the race on November 1.

Former Massachusetts Gov. Deval Patrick officially announced a late-entry 2020 presidential campaign on Thursday, and former New York Mayor Michael Bloomberg has been preparing for a potential run, recently filing paperwork for the Alabama and Arkansas presidential primaries. Should he run, Bloomberg is likely to largely skip the early nominating contests in Iowa.

Some candidates, who have been stuck in the single digits, have staked their campaigns on Iowa, believing it may be their best chance to make an impact in the still large field of Democrats.

At the end of last month, California Sen. Kamala Harris significantly cut costs to her campaign and redeployed staff from New Hampshire, Nevada and California to Iowa — further committing to her "all in on Iowa" strategy.

Former Housing and Urban Development secretary Julián Castro, who has struggled for months to raise money or get attention, said earlier this month he will reallocate resources to Iowa and Nevada and largely pivot away from New Hampshire and South Carolina.