With debates on horizon, Democrats sharpen attack lines

SAN FRANCISCO — Democratic presidential candidates who have spent months criticizing President TrumpDonald TrumpSenators introduce bipartisan infrastructure bill in rare Sunday session Gosar's siblings pen op-ed urging for his resignation: 'You are immune to shame' Sunday shows - Delta variant, infrastructure dominate MORE are beginning to turn their attention inward, testing attack lines against primary rivals ahead of debates that are likely to reshape what has so far been a genteel contest.
The new phase of the fight for the Democratic nomination kicked off this weekend in front of a crowd of about 3,000 at the California Democratic Party convention. They applauded calls to impeach Trump and to implement progressive policies. But they also clapped for the subtle digs the candidates took at one another and at the race's front-runner, former Vice President Joe BidenJoe BidenGOP report on COVID-19 origins homes in on lab leak theory READ: The .2 trillion Infrastructure Investment and Jobs Act Senators introduce bipartisan infrastructure bill in rare Sunday session MORE.
Biden skipped the confab to attend a Human Rights Campaign gala dinner in Ohio. Acting California Democratic Party Chairwoman Alexandra Gallardo-Rooker said Biden had promised he would visit California often in the near future.
In his absence, Biden — and the idea that he is a safe choice for the nomination — became a punching bag.
"There is a debate among presidential candidates who have spoken to you here in this room and those who have chosen for whatever reason not to be in this room about the best way forward," said Sen. Bernie SandersBernie SandersSenators introduce bipartisan infrastructure bill in rare Sunday session Bipartisan infrastructure win shows Democrats must continue working across the aisle 'The land is us' — Tribal activist turns from Keystone XL to Line 3 MORE (I-Vt.), referring to Biden's absence.
"In my view, we will not defeat Donald Trump unless we bring excitement and energy into the campaign and unless we give millions of working people and young people a reason to vote and a reason to believe that politics is relevant to their lives. We cannot go back to the old ways. We have got to go forward with a new and progressive agenda," Sanders told the crowd.
"Some Democrats in Washington believe the only changes we can get are tweaks and nudges. If they dream at all, they dream small," she told delegates. "The time for small ideas is over."
Other candidates promised a break with the past, another clear allusion to Biden's pledge to return to a more civil style of the politics.
"In these times, Democrats can no more keep the promise to take us back to the 2000s and the 1990s than conservatives can keep a promise to take us back to the 1950s. We can only look forward," South Bend, Ind., Mayor Pete ButtigiegPete ButtigiegSunday shows - Delta variant, infrastructure dominate Sunday shows preview: Delta concerns prompt CDC mask update; bipartisan infrastructure bill to face challenges in Senate Chasten Buttigieg: DC 'almost unaffordable' MORE said. "[Trump] wins if we look like defenders of the system. He wins if we look like more of the same. He wins if we look like Washington. So the riskiest thing we could do is try to hard to play it safe."
Biden, though, was not the only target as candidates polling low in the field sought to distinguish themselves.
Washington Gov. Jay InsleeJay Robert InsleeBipartisan governors press Biden administration on Canadian border restrictions Overnight Energy: Haaland, Native American leaders press for Indigenous land protections | Biden to return to pre-Obama water protections | Western governors ask Biden for aid on wildfires Western governors ask Biden for aid on wildfires MORE (D), who has qualified to make the debate stage later this month in Miami and who has made combating climate change the core of his campaign, said the two other governors seeking the Democratic nomination were less committed than he is to the cause.
"I'm the guy who banned fracking. There might be another couple of governors on the stage. They've done the opposite. They've embraced fossil fuels. I don't believe that's our future, so I'll have a different view from the other executives," Inslee told The Hill, referring to former Colorado Gov. John HickenlooperJohn HickenlooperManchin grills Haaland over Biden oil and gas moratorium It's time for US to get serious about cleaning up space junk Bipartisan group says it's still on track after setback on Senate floor MORE (D) and Montana Gov. Steve BullockSteve Bullock65 former governors, mayors back bipartisan infrastructure deal Arkansas, New Jersey governors to head National Governors Association Biden 'allies' painting him into a corner MORE (D).
Hickenlooper used his speech to attack the Sanders wing of the party, if not Sanders himself. A day before Sanders took the stage, delegates booed Hickenlooper as he urged his party to draw a clear distinction between socialism and Democratic candidates.
"If we don't draw a clear distinction between Democrats and our candidates and socialism, the Republicans will paint us into a corner that we can't get out of," Hickenlooper said in an interview. "In places like Ohio and Michigan and North Carolina and Wisconsin, places we have to win to beat Trump, we'll be starting out 10 yards behind."
The early contrasts are a hint of a sharper tone likely to define the Democratic contest during the summer and fall months. The change is borne in part of necessity — polls show Biden leading Sanders by a wide margin, with a handful of others trailing behind and a dozen or more candidates struggling even to register. 
Biden has spent his time on the trail focused on President Trump, staying above the Democratic fray. Sanders and a second tier that includes Warren, Buttigieg and Sen. Kamala HarrisKamala HarrisThe Hill's 12:30 Report - Presented by Facebook - CDC equates Delta to chickenpox in contagiousness Harris's bad polls trigger Democratic worries Why in the world are White House reporters being told to mask up again? MORE (D-Calif.) all need to drag Biden out of orbit. The candidates below them need to increase their own name recognition, and one path to achieving that goal is to pick a fight with a bigger fish — just as Biden is with Trump.
But party strategists, some affiliated with presidential campaigns and others unaligned, say there is an inherent danger in going negative in a primary before challenging Trump.
Several brought up the 2004 Democratic presidential fight, when a feud between former Vermont Gov. Howard Dean and then-House Minority Leader Richard Gephardt of Missouri opened the door to former Massachusetts Sen. John KerryJohn KerryHow the US could help Australia develop climate action Equilibrium/ Sustainability — Presented by NextEra Energy — Clean power repurposes dirty power No. 2 State Department official to travel to China amid tensions MORE and, to a lesser extent, former North Carolina Sen. John Edwards. Dean and Gephardt, long the front-runners in Iowa, ended up finishing third and fourth, respectively, in the first-in-the-nation caucuses.
The unusually crowded field and the way the first debates will operate could cause some uncertainty for the leading candidates. It is not clear in what order the 20 candidates who make the debate stage, in two groups of 10, will appear. An attack line aimed at Biden may not work if the candidate preparing it doesn't appear alongside the former vice president.
Some candidates are, for now, sticking with contrasts that reflect more positively on themselves rather than negatively on their rivals. In an interview, Sen. Kirsten GillibrandKirsten GillibrandTreat broadband as infrastructure and we have a chance to get it right House panel looks to help military sexual assault survivors To make energy green, remove red tape MORE (D-N.Y.) said she is preparing for the debates by coming up with "a concise way" to frame her decision to run for president.
"My story's really different from the other candidates running. I got my start in a 2-to-1 Republican district, won it twice, the second time by a 24-point margin," Gillibrand said.
Harris, the hometown senator who got her start in politics as San Francisco's district attorney, did not mention or allude to the rest of the Democratic field in her address to party faithful. Her biggest applause line came when she reiterated a call she had made earlier.
"We need to begin impeachment proceedings, and we need a new commander in chief," Harris said, to a standing ovation.