We’re less than two weeks from the Democrats’ first debate in Miami on June 26 and 27. I’m looking forward to the occasion — not so much because I’m eager to hear Bill de Blasio trying to drop some too-clever-by-half insults on the front-runners, but because the debates should help us exit a doldrums phase of the Democratic primary in which not a lot has been happening.

Until then, we’re left with some pretty slim pickings for Silver Bulletpoints. So I want to focus this week’s edition around the recent Selzer & Co. poll of Iowa, which was conducted on behalf of CNN, the Des Moines Register and Mediacom. While I’m a little bit reluctant to give that much attention to a single poll, this is one of the only recent high-quality polls of Iowa — and Selzer & Co. is pretty much as good as pollsters can get.

Bulletpoint No. 1: Things are looking up in Iowa for Warren and Buttigieg

The Selzer poll shows a closer race in Iowa than what we’ve been seeing nationally, with Joe Biden on top with 24 percent of the vote, followed by essentially a three-way tie for second with Bernie Sanders at 16 percent, Elizabeth Warren at 15 percent and Pete Buttigieg at 14 percent. Kamala Harris is next at 7 percent, with no one else above 2 percent.

That’s already a pretty decent result for Warren and Buttigieg — but, in fact, the poll is a bit better than it looks for them on the surface. Selzer also asked voters for favorability ratings on each candidate; I translated those ratings to a 5-point scale in which 5 means “very favorable” and 1 means “very unfavorable,” throwing out voters who didn’t know enough about a candidate to formulate an opinion.

On average, Buttigieg had the highest favorability ratings on the scale (4.1), with Harris (4.0) and Warren (4.0) close behind him. Biden’s (3.8) and Sanders’s (3.7) favorability ratings were decent but behind the top three. Meanwhile, while Cory Booker (3.7), Amy Klobuchar (3.6) and Beto O’Rourke (3.6) have little first-choice support, they retain decent favorables.

Buttigieg, Harris, Warren are viewed most favorably in Iowa Favorability ratings in the Selzer & Co. Iowa poll, June 2-5, 2019 Candidate Very fav. Mostly fav. Mostly unfav. Very unfav. Favorability score* First-choice support Buttigieg 32% 29% 7% 5% 4.1 14% Harris 30 33 8 5 4.0 7 Warren 37 34 10 7 4.0 15 Biden 36 37 14 9 3.8 24 Sanders 32 38 17 8 3.7 16 Booker 20 36 13 6 3.7 1 Klobuchar 12 32 13 4 3.6 2 O’Rourke 15 39 13 8 3.6 2 Castro 7 27 10 4 3.5 1 Inslee 5 16 7 3 3.4 1 Bullock 5 14 8 2 3.4 0 Swalwell 5 17 9 4 3.3 0 Gillibrand 7 31 17 6 3.3 0 Hickenlooper 6 18 12 4 3.3 0 Bennet 3 16 9 3 3.3 1 Delaney 6 21 12 5 3.3 1 Yang 5 14 10 5 3.1 1 Moulton 3 9 8 3 3.0 0 Ryan 2 14 10 4 3.0 0 Gabbard 5 18 11 9 3.0 1 Williamson 2 7 11 7 2.5 0 de Blasio 2 14 27 13 2.4 0 Messam 1 1 6 3 2.2 0 * Calculated based on a weighted average of favorability ratings, giving a candidate 5 points for a “very favorable” rating, 4 points for “somewhat favorable,” 2 points for “somewhat unfavorable” and 1 point for “very unfavorable,” and ignoring voters who don’t know or don’t have an opinion about the candidate. Favorability ratings were calculated by a weighting of 90 percent of the responses from those who plan to caucus in person and 10 person of responses from those who plan to participate in the caucuses virtually.

I don’t have any hard-and-fast rule about how much to emphasize favorability ratings against first-choice support. It’s probably worth noting that President Trump’s favorables were often mediocre in polls of 2016 Republican voters, but he won the nomination anyway. Still, the Selzer poll is consistent with a story where voters who are paying more attention to the campaign are ahead of the curve on Warren and Buttigieg. And Warren and Buttigieg are good candidates for Iowa with a legitimate shot to win there.

Bulletpoint No. 2: Who makes for a good Iowa candidate, and who’s campaigning there?

What do I mean by a good candidate for Iowa? If I designed a candidate in a lab to win the Iowa caucuses, I’d want them to have four characteristics:

Perform well with liberal voters, since voters in the Iowa caucuses are pretty liberal.

Perform well with white voters, since Iowa is pretty white.

Be strong retail campaigners with good organizational skills.

Be from the Midwest.

Warren checks three-and-a-quarter boxes: She polls well among white liberals, she has a strong organization in Iowa, and she sorta counts as Midwestern if you think of her as being from Oklahoma rather than Massachusetts (and if you count Oklahoma as Midwestern). Buttigieg checks at least three boxes: He overperforms with white voters (and underperforms with minorities), he’s Midwestern, and by most accounts he’s a good retail campaigner. Sanders also checks three boxes (everything except the Midwest one).

But are the candidates who are the most Iowa-appropriate actually campaigning there more often? Last month, my colleague Nathaniel Rakich looked at which candidates have campaigned the most in Iowa and New Hampshire. I’m going to provide a twist by accounting for how long a candidate has been in the race. For instance, John Delaney has spent the most days in Iowa, but he’s also been campaigning for president since July 2017 (!).

Bullock, O’Rourke and Ryan are focusing the most on Iowa Share of days with an Iowa event since campaign launch for the 2020 Democratic presidential candidates, through June 12, 2019 Candidate First day of CAMPAIGN No. of Days Days with Iowa events Share of days with Iowa events Bullock 5/14/19 30 7 23.3% O’Rourke 3/14/19 91 19 20.9 Ryan 4/4/19 70 12 17.1 de Blasio 5/16/19 28 4 14.3 Swalwell 4/9/19 65 8 12.3 Williamson 1/28/19 136 15 11.0 Klobuchar 2/10/19 123 13 10.6 Warren 12/31/18 164 17 10.4 Sanders 2/19/19 114 11 9.6 Bennet 5/2/19 42 4 9.5 Gillibrand 1/15/19 149 14 9.4 Booker 2/1/19 132 12 9.1 Hickenlooper 3/4/19 101 9 8.9 Delaney 7/28/17 685 57 8.3 Biden 4/25/19 49 4 8.2 Buttigieg 1/23/19 141 11 7.8 Gabbard 1/11/19 153 11 7.2 Inslee 3/1/19 104 6 5.8 Yang 2/10/18 488 28 5.7 Castro 1/12/19 152 8 5.3 Harris 1/21/19 143 7 4.9 Moulton 4/22/19 52 1 1.9 Gravel 3/19/19 86 0 0.0 The five leading candidates in the most recent Selzer & Co. poll of Iowa are highlighted. Campaign launch dates reflect when candidates formed an exploratory committee, even if they hadn’t formally launched their campaign, since candidates generally do engage in campaign-style events during the exploratory phase. However, events only count if they occurred on or after the launch date listed in the table. Source: Des Moines Register Candidate Tracker

Measured by the proportion of days with an Iowa event since their campaigns began, the most Iowa-centric candidates have been Steve Bullock, O’Rourke and Tim Ryan. Among the top tier, Harris has spent a notably lower share of her time in Iowa than the others. Perhaps that makes sense — she doesn’t check a lot of the boxes I described above. But it may also explain why she isn’t converting high favorability ratings into much first-choice support.

Bulletpoint No. 3: Biden is falling back to the pack

Six weeks ago, amidst Biden’s polling surge, I put him an extra step ahead of the other Democrats in my periodically updating, not-to-be-taken-too-seriously presidential tiers, demoting Sanders, Buttigieg and Harris from tier 1b to tier 1c and leaving tier 1b blank to indicate the distance between Biden and everyone else.

But we’ve promised to make these tiers fairly polling-driven, and while the decline in Biden’s national numbers is predictable — pretty much all the previous candidates to get bounces have also seen them fade — I err on the side of paying more attention to Iowa and New Hampshire polls than to national ones. So that Selzer poll in Iowa is enough for me to repromote Sanders, Buttigieg and Harris back to tier 1b and to move Warren to there for the first time.

Nate’s not-to-be-taken-too-seriously presidential tiers For the Democratic nomination, as revised on June 13, 2019 Tier Sub-tier Candidates 1 a Biden b Warren ↑, Sanders ↑, Buttigieg ↑, Harris ↑ 2 a O’Rourke b Booker, Klobuchar 3 a Yang, Castro, Abrams* b Inslee, Gillibrand, Gabbard c Bullock, Hickenlooper, Ryan, Bennet, de Blasio, Williamson * Candidate is not yet officially running but may still do so.

For Sanders, Warren and Buttigieg, the case for promotion is reasonably clear. They’re all plausible Iowa winners — and if they win Iowa, they’ll have a pretty good shot at New Hampshire. I continue not to be super-duper impressed by Sanders’s polling, but he’s fairly consistently held on to second place nationally, and I’m not going to try to overthink things too much. Warren has some momentum, even if it’s a little overstated by the national media. Buttigeg’s modest name recognition could give him room to grow later, as he already seems to be doing in the early states.

Harris is the trickiest case, but her favorables remain pretty good, she’s a decent bet to do well at the debates, and it seems unlikely that a party in which 40 percent of voters are nonwhite is going to be entirely content choosing between three or four white candidates. All that said, Harris could also have a Marco Rubio-esque problem of being broadly acceptable but few voters’ first choice.