The Clinton campaign received a wake-up call when a recent poll indicated the former secretary of State’s once-commanding lead in Iowa has fallen to just 7 points over rising candidate Sen. Bernie Sanders, I-Vt.

According to the Des Moines Register/Bloomberg Politics poll, Clinton is leading with support from 37 percent of likely Democratic caucus-goers, while Sanders holds 30 percent. The poll’s margin of error is plus or minus 4.9 percentage points.

“This is definitely a big development for both Bernie Sanders and Hillary Clinton,” said Justin Holmes, an assistant professor of political science at the University of Northern Iowa.

Holmes said until recently Sanders’ numbers were going up but Clinton’s numbers weren’t necessarily going down; Sanders was mostly picking up undecided voters. This poll indicates Sanders is now also picking up Clinton voters as well, he said.

“For Clinton, this is a wake-up call,” Holmes said. “Clinton will have to start acknowledging her competition more now that she looks a lot more vulnerable.”

In May, the poll had Clinton at 57 percent, while Sanders had 16 percent. This is the first time the poll had Clinton’s support under 50 percent.

The Clinton campaign hasn’t been blind to this poll, and her people say they’ve been ready for a competitive race.

“We’ve said from the beginning this would be a competitive caucus, and that’s why we have 47 organizers, with more to come, working across the state talking with Iowans,” said Patrick Burgwinkle, a Clinton campaign spokesman.

On the other side, the Sanders campaign was quick to acknowledge this new poll and Sanders’ growing support among Iowans.

“What this new poll shows is that the more Iowans get to know Bernie, the better they like him and what he stands for,” said Michael Briggs, the communications director for the Sanders campaign, in a press release Aug. 29. “We’ve seen the same thing in New Hampshire and across the country.”

Holmes said he was surprised on how much support Sanders has garnered among Iowans recently.

Holmes said he believes part of Sanders success stems from his ability to tap into people’s frustration with politics.

He said Clinton is in many ways, the ultimate inner politico being both a former first lady and the former secretary of State. Sanders, on the other hand, seems to turn away from typical party politics and is far more left than his fellow candidates, Holmes said.