Vermont Sen. Bernie Sanders is catching up to Democratic front-runner Hillary Clinton in the critical early-caucus race in Iowa, a new poll by the state's largest newspaper revealed.

Sanders now trails the former secretary of state by only 2-percentage points -- a statistical tie -- according to the Iowa poll the Des Moines Register and Bloomberg Politics conducted between Jan. 7 and Jan. 10. A month ago, Clinton was still up by 9 points, the paper noted.

Among likely Iowa caucusgoers, 42 percent now favor the former New York senator who has long dominated surveys on the national level. Sanders scored 40 percent in the poll, whose margin of error statisticians put at plus or minus 4.4 percentage points.

'Bernie is around to stay'

Grant Woodard, a Des Moines lawyer who has worked on several state and national Democratic campaigns, said the results showed that the Vermont lawmaker has to be considered a serious competitor in the racy for the party's 2016 nomination.

"It shows Bernie is around to stay for sure. It's not a fly-by-night thing," Woodard, analyzed. "It really shows we're going to have a pretty crazy last few weeks here."

The Hawkeye state is set to hold its caucuses on Feb. 1, kicking off a busy primary calendar that soon after will feature races in New Hampshire (Feb. 9) and -- on the Democratic side -- in Nevada (Feb. 20), according to the New York Times.

And as the first-in-the-nation caucus approaches, the momentum clearly seems to be on Sanders' side, the Des Moines Register noted. The senator has seen his support rise by 1-percentage point in the past month, while Clinton has slipped from 48 percent to 42 percent. Former Maryland Gov. Martin O'Malley, the third candidate in the race, meanwhile, scored 4 percent.

Sanders doing well among key demographics

Ann Selzer, who conducts the Iowa Poll, explained that Sanders was performing particularly well with demographic groups that also helped then-Sen. Barack Obama win the state's caucuses in 2008.

"That to me is the reason why this race is close," she said.

And the Vermont lawmaker's backers feel strongly about his principled stance on income inequality and other social issues, the pollster added.

"Sanders supporters are not thinking it's a big deal to support a candidate who might not win the general election," Selzer said.

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