In this holiday weekend edition: What to read, what the candidates are up to and how the left-wing primaries are shaping up.

Keep enjoying your weekend, especially if you're running for president. This is the Trailer.

Memorial Day weekend is the last lull in presidential campaigning before the race really takes off. On Saturday, most of the 2020 field will be gathering in San Francisco for the country's biggest state party event. A week after that, the candidates will swarm into Cedar Rapids, Iowa, for the Democratic “hall of fame” gala. A few days later, they’ll learn who did and didn't score a slot in the first televised debates.

Here are two threads to follow over coming weeks.

The Biden Identity. The leader in Democratic primary polls has not held a public event in eight days, since his major campaign address in Philadelphia. Joe Biden is not yet scheduled to address the California Democratic Party convention. He's not among the 17 candidates confirmed for the June 9 cattle call in Iowa. At fundraisers, he basically has been delivering a version of his stump speech — no gaffes, no questions, no errors.

That has made the former vice president the only leading Democratic candidate running a traditional front-runner campaign. Every other contender, starting with Sen. Bernie Sanders (I-Vt.), views constant organizing and campaigning as the way to break out in an early state. After one full month of campaigning, Biden has spent just two days in Iowa and two in New Hampshire. Sanders will have appeared more in New Hampshire over just this weekend.

Biden's doing this with less built-in support than last cycle's Democratic favorite. On Memorial Day 2015, Hillary Clinton led Sanders by an average of 52 points in Iowa and by 37 points in New Hampshire. (She ended up winning Iowa by 0.2 points and losing to Sanders in New Hampshire.) In both states, Biden's advantage over the field is a fraction of her early polling leads. His edge now looks similar to the one pollsters found six months ago, with no candidate chipping away significantly. If any candidate breaks out, the change could start this week. The president has driven attention toward Biden by repeatedly attacking him, but other Democrats may get time to command attention.

Antiabortion Democrats? As soon as this week, Louisiana Gov. John Bel Edwards may be handed legislation that would ban abortion after a fetal heartbeat is detected. Unlike nearly every other Democrat in office, Edwards has signaled that he would sign the bill into law. He is not the first Democratic governor to oppose abortion, but he would be the first to do so facing the demands of the current antiabortion movement, which is looking for a test case to unravel the precedent on abortion rights set by the U.S. Supreme Court.

No Democratic presidential candidate opposes abortion rights. Soon, they will probably be asked if they believe in a tent big enough for Edwards and Mississippi gubernatorial candidate Jim Hood, who also opposes abortion. The answer even 10 years ago was yes, and the answer in 2019 is to be determined.

READING LIST

"Supreme Court says Ohio and Michigan do not have to come up with new maps immediately,” by Robert Barnes

The news here is in what isn't happening: After state courts struck down gerrymandered congressional maps, the Supreme Court stayed any changes for the time being.

“Sanders’s education plan renews debate over charter schools and segregation,” by Dana Goldstein and Sydney Ember

Sen. Bernie Sanders's campaign is waging populist assaults on powerful interests. For-profit charter schools have lots of resources and allies for their pushback.

“Jay Inslee has a plan for saving Earth. So why is he at 0.8 percent in the polls?” by Will Bunch

The climate-focused governor of Washington state is polling behind other “single-issue” candidates, but the substance of his plans is winning liberal respect.

“Trump and allies take aim at Biden — and his family — as their top Democratic target,” by Matt Viser and Ashley Parker

The president's reelection campaign has a playbook that worked once, in 2016. Why not run the same plays now?

"'Seniors for Buttigieg': Why voters twice his age feel drawn to the millennial mayor,” by Dan Merica

Older Democrats, many of whom wistfully compare new presidential candidates to the Kennedys, have been among the strongest supporters of the Democrats' youngest presidential hopeful.

“Democrats don’t want to nominate a candidate who looks like Bernie or Joe,” by Gabriele Magni and Andrew Reynolds

The current polling strength of two elderly white men might be an outlier for Democratic voters.

“Trump campaign embraces groups trying to court minority voters — one with false pitches,” by Michael Scherer

The Republican Party’s outreach has shifted away from the compassionate post-2012 approach.

AD WATCH

Protect Our Care, a 501(c)(4) group created after the 2016 election to rescue the Affordable Care Act, is spending at least $1 million on digital ads promoting 20 freshman House Democrats. Each ad has the same basic script — some praise for the House-passed pharmaceutical and health-insurance bills that are unlikely to move in the Senate.

These spots are part of the toolbox for incumbents. At a similar point in 2017, the pro-GOP American Action Network ran digital ads in targeted House districts, encouraging voters to thank the members of Congress who voted to repeal the ACA.

Any long-term benefits from those ads were hard to spot in the November 2018 election. Most of the swing-seat Republicans who backed the bill were wiped out. At the moment, nothing House Democrats have done is particularly unpopular, nor does it have much in the way of grass-roots political opposition. And none of it is moving through the Senate.

2020

Sen. Bernie Sanders (I-Vt.). He launched another busy week of campaign events with a speech in Montpelier, Vt., with a punchy (albeit) defensive message: “I make no apologies.” After the New York Times looked into Sanders's advocacy for Nicaragua's left-wing government in the 1980s, a mainstream left-wing position at the time, he emphasized his decades of opposition to military adventure.

“I am doing everything that I can to prevent Donald Trump and John Bolton from taking us into a war with Iran — a war which would be much worse than the war in Iraq,” Sanders said. “I make no apologies for that, either.”

Pete Buttigieg. The South Bend, Ind., mayor's appearance at a Washington Post Live event brought new attention to a focus of his recent campaign appearances: Attack the Trump administration on foreign policy. At stops in New Hampshire and New York, he criticized the decision to send 1,500 military personnel to the Middle East and emphasized that, unlike the president, he had worn the uniform.

Sen. Amy Klobuchar (Minn.). During a weekend campaigning in Iowa, she introduced her “priorities for America's farmers,” some of which build on legislation she already has introduced. Among the highlights: raising the cap to $10 million on Chapter 12 bankruptcies, more tightly regulating renewable fuel standard (RFS) waivers and providing bigger loans to farmers.

Joe Biden. He will head to Houston on Tuesday for town hall with the American Federation of Teachers, following on events organized with AFT President Randi Weingarten for Sanders and Sen. Elizabeth Warren (D-Mass.).

Sen. Kamala D. Harris (Calif.). She's filming a CNN town hall in Spartanburg, S.C., on Tuesday night, then traveling around the upper reaches of the state for meet-and-greets.

Rep. Seth Moulton (Mass). He's embarking on a three-state Veterans Mental Health Tour, starting in his Massachusetts district Tuesday night and continuing through South Carolina and Nevada.

Jay Inslee. The Washington governor announced Friday that more than 65,000 people had donated to his campaign, which is likely to secure him a place onstage in the first primary debates next month.

Sen. Elizabeth Warren (Mass). She's spending the holiday weekend in Iowa, making six stops across the state, including her first in the left-leaning city of Fairfield. The city has hosted several candidates — Rep. Tulsi Gabbard (Hawaii), Sanders and activist Marianne Williamson — as they jostle to own the “liberal lane” of the primary.

Beto O'Rourke. The former Texas congressman said on CBS's “Face the Nation” that he didn't buy the Trump administration's rationale for sending troops to the Middle East. “I have a really hard time believing this administration and believing a president who has so wantonly lied and misconstrued the facts at every single turn to his own gain.”

Bill de Blasio. He told CNN's “State of the Union” that his close understanding of Donald Trump made him an ideal 2020 foe. “I know something about Donald Trump that's different from the other candidates, because I have watched him for decades. I understand his game plan. I understand his tricks and his strategies,” he said. “And I do get under his skin.”

DEMS IN DISARRAY

The decision by Democratic Congressional Campaign Committee Chair Rep. Cheri Bustos (D-Ill.) to scrap a fundraiser for Rep. Daniel Lipinski (D-Ill.) was a coup for the party's left — and it needed one. While challengers have continued to climb into the 2020 primaries, some of the left's most obvious targets, such as Rep. Henry Cuellar (D-Tex.), have no serious opponents.

In the meantime, challengers are looking for incumbents to make mistakes. Lipinski told Politico last week that he was getting an earlier start on his 2020 race — Illinois' primaries are less than 10 months away — and was ready to portray challenger Marie Newman as too radical.

The race for New York's 10th Congressional District, represented since 1993 by Rep. Jerrold Nadler (D-N.Y.), has not received the same attention. In an interview, Nadler challenger Lindsey Boylan, a former gubernatorial aide, said she intended to ask why Nadler has not requested from the National Archives legal documents written by Brett M. Kavanaugh while he was working in the George W. Bush administration, before he was confirmed to the U.S. Supreme Court. Activists believe that if Kavanaugh challenged the constitutionality of legal abortion in memos that were not released ahead of his confirmation, they can pressure him to recuse himself on abortion matters before the court.

“This is life or death for women,” Boylan explained. “Jerry Nadler could get these documents with the stroke of a pen.”

At issue in both primaries: How would a surge in voter turnout, and new nervousness about the fate of Roe v. Wade, affect the electorate? Lipinski's narrow win over Newman in 2018 can be attributed, in part, to higher voter turnout — 92,108 ballots were cast — and a competitive Democratic primary for governor pulling out less-regular voters. He was also helped by what appeared to be a lack of a competitive Republican primary. Illinois voters can select their party ballot at the polls, which allowed conservatives to back Lipinski.

The next round of primaries will look different. Lipinski's primary is the same day as the presidential primary, which has seen skyrocketing turnout in the past. Nadler and Boylan will be on the ballot in the first primary since New York's Democratic legislators moved up the registration deadline. Instead of registering as Democrats in October in the year before the primary, voters can register as Democrats 60 days before the primary. That could mean thousands of new voters will decide the fates of the incumbents, and their challengers want to accentuate how they would govern from the left.

COUNTDOWN

. . . Six days until MoveOn's ideas forum in San Francisco
. . . 17 days until the cutoff for the first Democratic presidential debates
. . . 26 days until Rep. James E. Clyburn's fish fry