An NBC News poll released Tuesday shows Mississippi U.S. Senate candidates Mike Espy and Cindy Hyde-Smith neck and neck, with Chris McDaniel remaining in striking distance and a large number of undecided voters.

Both Democrat Espy and Republican McDaniel viewed the poll as welcome news, coming on the same day President Donald Trump planned to hold a rally in support of Republican Hyde-Smith in Southaven.

Watch Live: Watch live: Trump holds Mississippi rally for Cindy Hyde-Smith

The poll showed:

Espy: 25 percent

Hyde-Smith: 24 percent

McDaniel: 19 percent

Toby Bartee (Democrat): 4 percent

Undecided: 27 percent

"This poll, just like others, shows the momentum Mike Espy has in Mississippi," his campaign manager, Oleta Fitzgerald, said in a release. "This poll confirms that Mississippi voters are tired of the same old Left versus Right political rhetoric."

McDaniel campaign spokesman Tanner Watson issued a statement that said, "Whether you're referencing (a poll done for a McDaniel-supporting PAC) that has us leading by 8 points or NBC's poll that has us within 5, the numbers demonstrate what we are seeing on the ground in Mississippi ... Powered by hard-working volunteers across Mississippi, our momentum is surging, and Hyde-Smith's campaign is fading."

Hyde-Smith's campaign could not immediately be reached for comment due to the Trump visit.

The special election race on Nov. 6 is likely to go to a runoff on Nov. 27.

The online poll, conducted for NBC News by SurveyMonkey from Sept. 9-Sept. 24 of 1,152 adults including 985 registered voters estimated a margin of error of +/-4.3 percentage points.

Some political observers and other pollsters have questioned the accuracy of online polling and specifically SurveyMonkey polls. The FiveThirtyEight blog, which grades major polling organizations on their accuracy, listed SurveyMonkey near the bottom in accuracy this year.

In Mississippi's regular Senate race, the poll showed incumbent Republican Sen. Roger Wicker leading Democratic state Rep. David Baria, 43 percent to 29 percent, with 27 percent undecided.

The poll showed 35 percent of respondents strongly approve of the job Trump is doing, 17 percent somewhat approve, and 37 percent strongly disapprove.