What’s the problem with these polls?

This week three prominent polls of New Hampshire Democrats have been released, and each one had a different candidate leading the pack.

This weekend CBS News released a poll that put Sen. Warren out front—just barely—with 27 percent support.

On Tuesday, Emerson College released their New Hampshire poll with Warren at 21 percent and former Vice President Joe Biden in the lead with 24 percent.

The next day, a Boston Herald/Franklin Pierce College poll put Warren way down at just 17 percent and Sen. Bernie Sanders on top with 20 percent.

Three polls, three different frontrunners, all in the same week. And it’s not just the candidates rank that’s changing poll to poll. The differences in their levels of support are huge, too. Biden’s numbers in New Hampshire are relatively steady, between 21 and 26 percent.

Not so for Bernie Sanders. Factor in the polls’ margins of error, and Sanders’ support among Granite State Democrats could be as high as 30 percent or as low as 13 percent.

Then there’s Warren, who is either at 12 percent (Boston Herald) or 32 percent (CBS),  a 30-point swing.  And it’s not just New Hampshire: Two national polls released on the same day by Reuters and The Economist put Warren at 11 and 26 percent respectively.

What should voters—Democrats in particular—do with these numbers?

“Ignore them!” says Kathy Sullivan, former NH Democratic Party chair. “Go out, see the candidates, and decide whom you like the best.”

DC-based Republican strategist Craig Stevens agrees. “We’re still months away from voting, the polls will shift and change – voters should focus on determining which candidate is the best skilled, prepared, and suited to be president,” he told InsideSources.

This is generally the advice of political pros regarding all early polling — ask a Harris or Buttigieg staffer about polls and get ready for a 15-minute discourse on how Bill Clinton was in single-digits at this point in 1991.  But that advice may be even more on point in New Hampshire.

“Polling here is extremely difficult due to the state laws preventing automated calls to people on the do-not-call lists, which eliminates almost four out of five eligible phone numbers,” says Ross Berry, a Granite State campaign veteran and president of the political firm Vote Adjustments. “This dramatically increases the cost for more accurate polls as they must be initiated and conducted by a live agent.”

So, is polling fundamentally untrustworthy? Should polls be ignored entirely? That’s the argument often made by Trump supporters who insist the president has a path to victory despite a national approval rating that hovers around 40 percent. They point to the contradictory numbers from poll to poll as evidence the science itself simply isn’t reliable.

However, while polls during the long 2016 campaign gave Hillary Clinton a big lead, surveys taken a week before the November election showed the race was close. As Sean Trende of RealClearPolitics notes, “the final RCP Four-Way National Poll Average showed Hillary Clinton winning the popular vote by 3.3 points.” The final result was Clinton by 2.2 percent.  The polls were right, if viewed as a snapshot of a moment in time, rather than a predictor of future events.

And there is some information in these polls Democrats might find useful, such as the fact that Warren consistently fares poorly against President Trump in head-to-head match-ups despite her popularity with the progressive base.

Meanwhile, pollster David Paleologos of the Suffolk University Political Research Center does see a trend across all of these seemingly-contradictory polls: “The political cement is hardening around the top three candidates,” he told InsideSources.

“Democratic choices are beginning to harden,” Paleologos recently wrote for USA Today. “Though national polls may disagree over the front-runners’ exact order or percentages, they do show how the Democratic form is solidifying.”