Welcome to Pollapalooza, our weekly polling roundup.

Poll(s) of the week

Fresh off a strong performance in Iowa, Sen. Bernie Sanders is ahead by 9 percentage points in our New Hampshire polling average and has a 74 percent chance of winning Tuesday’s primary, according to our forecast. That may sound like Sanders is an overwhelming favorite in the Granite State, but the race is still wide open. If the primary were held multiple times, Sanders would lose New Hampshire about 1 in 4 times, according to the forecast — about as likely as flipping a coin twice and getting heads both times.

Why is there so much uncertainty about the New Hampshire outcome, given Sanders’s lead in the polls? First of all, it’s a primary, and polling primaries is notoriously difficult: A larger share of voters in primaries are open to switching between candidates. And there will be several opportunities for New Hampshire voters to do between now and Tuesday. For one, the mess in Iowa is still sorting itself out. Former South Bend, Indiana, Mayor Pete Buttigieg, who our forecast thinks has a 20 percent chance of winning the state, could potentially benefit from the victory he claimed in Iowa. Friday’s Democratic debate could also sway voters, so we’re waiting for more polling.

Just how big is this group of people that could still change their mind? Polls have found that about two-fifths of likely Democratic primary voters in New Hampshire say they might change their mind before next Tuesday’s primary, though voters’ commitment varied by candidate.

A Suffolk University poll conducted after the Iowa caucuses found 43 percent of likely primary voters said they could change their mind. Among Sanders supporters, 6o percent said their mind is made up. Sixty-seven percent of former Vice President Joe Biden’s supporters and 59 percent of Buttigieg supporters said the same, compared to about 45 percent of Sens. Elizabeth Warren and Amy Klobuchar’s supporters. (Overall, the poll reported Sanders leading the field with 25 percent support, Buttigieg second at 19 percent, Biden at 12 percent and Warren at 11. Fourteen percent of respondents also said they were undecided.)

A University of Massachusetts Lowell poll conducted in late January — before Iowa — found that 39 percent of likely New Hampshire primary voters said they could still change their mind. Sanders’s support was firmer in this poll: Of the 23 percent who picked Sanders as their first choice, 88 percent said they will definitely cast their vote for him. Sixty-eight percent of Biden’s supporters were firm, as were 62 percent of Warren’s, 42 percent of Klobuchar’s and 29 percent of Buttigieg’s.

A recent Saint Anslem College poll of New Hampshire — also conducted before Iowa — found 41 percent of respondents said their preferred candidate could change. Among respondents who said they were firm in their choice, Sanders led with 25 percent support. Twenty-two percent supported Biden, 18 percent Buttigieg, 11 percent Warren and 9 percent Klobuchar. Of those who said they could change their mind, 22 percent supported Biden, 17 percent Klobuchar, 16 percent Sanders, 14 percent Warren and 13 percent Buttigieg. (Among likely voters, this poll reported Biden and Sanders tied at 19 percent support, Buttigieg with 14 percent and Klobuchar and Warren with 11 percent.)

And a recent Monmouth University poll of New Hampshire — partially taken after Iowa — found that only 49 percent of likely primary voters are firmly decided in their choice, and 46 percent are open to a different candidate. That 46 percent includes 11 percent who said there is a “high possibility” they could change their mind, 25 percent who said there is a “moderate possibility,” and 10 percent who said there is a “low possibility.” Among respondents who make between $50,000 and $100,000, just 43 percent are firmly decided. Buttigieg and Sanders have the most support among that group, each with 21 percent support. (Overall, the poll reported Sanders with 24 percent support from likely voters, Buttigieg with 20 percent, Biden with 17 percent and Warren with 13 percent.)

Taken together, the polling suggests somewhere close to half of New Hampshire voters say they are capable of switching candidates. While a few polls show Sanders with the most loyal following, others have Biden ahead or close behind. The real question is, given the fluidity of the New Hampshire electorate, how many supporters could either pick up? Could voters shift to Buttigieg or Warren, or both, instead? Polling over the next few days will give us some clues, but don’t be surprised if there’s a lot of last-minute movement.

Oh! And there’s a three-hour debate tonight in Manchester, New Hampshire, hosted by ABC News, WMUR-TV and Apple News. This debate will be one of the candidates’ last chances to make their pitch to some of those persuadable New Hampshire voters.

Other polling bites

The notion that Iowa and New Hampshire should go first in the Democratic primary process might be popular in Iowa and New Hampshire, but nationally, not so much. In the recent UMass Lowell poll, 67 percent of likely New Hampshire voters said Iowa and New Hampshire should continue to go first in future presidential primaries. But nationally, only 20 percent of Democrats said Iowa and New Hampshire should go first, while 34 percent said other states should go first and 46 percent were not sure, according to a February Economist/YouGov poll.

In that recent UMass Lowell poll, likely New Hampshire voters were asked if they prefer President Trump win reelection on Nov. 3 or “a giant meteor strikes the earth, extinguishing all life.” Sixty-two percent said they prefer the meteor strike. When broken out by income, gender, age and ideology, the only group in which a majority of respondents chose Trump’s reelection were those making more than $100,000 per year.

Americans are feeling particularly optimistic about their personal finances. A record-breaking 59 percent of Americans said they are better off financially now than they were a year ago, according to a recent Gallup poll. That’s the highest it’s been since Gallup started asking the question in 1977. In that same poll, 74 percent also predicted they will be better off financially a year from now (again the highest since 1977). However, the breakdown is fairly partisan: While 76 percent of Republicans said they are better off now than a year ago, only 43 percent of Democrats said the same.

Pew Research Center recently looked at how popular each of the candidates polled among religious groups within the Democratic Party. Biden led among Christian and Jewish voters — 36 percent of Protestants, 34 percent of Catholics and 31 percent of Jewish voters said the former vice president was their first choice. His support was even higher among black Protestant Democratic voters (44 percent). At 28 percent, Sanders led among unaffiliated voters (atheists, agnostics and “nothing in particular”).

Trump is the most popular president among Republicans and Barack Obama is the most popular president among Democrats, according to a recent YouGov poll. Thirty percent of Republicans said Trump is the best president, followed by 22 percent who said Ronald Reagan and 10 percent who said George Washington. Among Democrats, 23 percent said Obama was the best, followed by 13 percent who said Franklin Delano Roosevelt and 11 percent who said Abraham Lincoln.

Trump approval

According to FiveThirtyEight’s presidential approval tracker, 43.9 percent of Americans approve of the job Trump is doing as president, while 51.8 percent disapprove (a net approval rating of -7.9 points). At this time last week, 42.9 percent approved and 52.7 percent disapproved (for a net approval rating of -9.8 points). One month ago, Trump had an approval rating of 42.0 percent and a disapproval rating of 53.3 percent, for a net approval rating of -11.3 points.

Generic ballot

In our average of polls of the generic congressional ballot, Democrats currently lead by 5.7 percentage points (47.2 percent to 41.5 percent). A week ago, Democrats led Republicans by 5.6 points (46.9 percent to 41.3 percent). At this time last month, voters preferred Democrats by 6.6 points (47.5 percent to 40.9 percent).