Joseph R. Biden may have sewn up the Democratic presidential nomination, but that has not translated into unity in a party where a sizable chunk of voters is still turning out to vote against him in primary elections.<\/p>\n

In Tuesday\u2019s primary in the District of Columbia, Sen. Elizabeth Warren of Massachusetts, who dropped out of the race three months ago, won 12% of the primary vote, and Sen. Bernard Sanders captured another 10%.<\/p>\n

In Rhode Island, Mr. Sanders collected 15%. In Pennsylvania, he got 18%. In the slate of contests last week, Mr. Biden struggled to top 75%.<\/p>\n

With the country roiled by racial unrest and still dealing with the COVID-19 pandemic, the Democrats\u2019 left wing says Mr. Biden is bungling a chance to stand for real change in November.<\/p>\n

\u201cI don\u2019t think anyone would expect Joe Biden would tattoo defund the police on his arm over the last couple of days, but he is kind of betraying an inability to listen to the people on the ground who are frankly putting their lives on the line,\u201d said Neil Sroka, a spokesman for Democracy for America, a liberal activist group.<\/p>\n

Some on the left were cringing after Mr. Biden refused to back the \u201cdefund the police\u201d movement and asserted that black voters \u201cain\u2019t black\u201d if they don\u2019t support him over President Trump.<\/p>\n

They say Mr. Biden, 77, is walled off from the grassroots and has surrounded himself with people pushing a less-inspiring vision that has been molded by the party\u2019s corporate wing.<\/p>\n

The intraparty tension has made Mr. Biden one of the weakest primary winners in modern history, but the problems have been overshadowed by world crises and the news cycle dominance of Mr. Trump.<\/p>\n

Solana Patterson-Ramos, a community organizer in Milwaukee, said she has focused on politics that are local rather than presidential.<\/p>\n

\u201cI had to look up and see what was going on,\u201d said Ms. Patterson-Ramos, who backed Mr. Sanders in the primary.<\/p>\n

\u201cNo one is like, \u2018Yeah, Biden.\u2019 Let\u2019s just be real,\u201d she said.<\/p>\n

FiveThirtyEight showed how weak Mr. Biden was in the primaries based on his early vote total.<\/p>\n

The analysts say he won just 42% of all primary votes cast at the time he became the presumptive nominee in April. That was the worst showing for any party pick since Walter Mondale in 1984.<\/p>\n

Since then, his performance has been uneven.<\/p>\n

He won 84% of the primary vote in Georgia this week but just 65% in West Virginia.<\/p>\n

Mr. Trump experienced something similar in 2016. After he sewed up the nomination, large numbers of Republican voters cast ballots against him in later primaries. The bad blood carried through to the convention. Former opponent Sen. Ted Cruz of Texas refused to endorse him and received a shower of boos.
<\/br>Mr. Biden has done better on that score.<\/p>\n

Mr. Sanders and Ms. Warren endorsed the former vice president shortly after pulling the plugs on their bids. Since then, Mr. Biden has tapped Rep. Alexandria Ocasio-Cortez of New York, a star on the far left and particularly among young voters, to be a top adviser on climate change.<\/p>\n

Yet when it comes to issues, Mr. Biden isn\u2019t tacking in their direction.<\/p>\n

To the chagrin of activists during the primary battle, Mr. Biden refused to go all-in on a wish list of priorities that included the Green New Deal, forgiving student debt and \u201cMedicare for All.\u201d<\/p>\n

He pumped the brakes this week on slavery reparations for black Americans. He said he wanted to study the issue of payments and insisted that American Indians must be included.<\/p>\n

Where activists are demanding a complete overhaul of policing in America, including stripping down department budgets, Mr. Biden, in an op-ed in USA Today, said the answer was to bolster budgets. He offered $300 million in federal funding to \u201creinvigorate community policing.\u201d<\/p>\n

\u201cWhile I do not believe federal dollars should go to police departments that are violating people\u2019s rights or turning to violence as the first resort, I do not support defunding police,\u201d Mr. Biden wrote in the op-ed. \u201cThe better answer is to give police departments the resources they need to implement meaningful reforms, and to condition other federal dollars on completing those reforms.\u201d<\/p>\n

Mr. Sroka said Mr. Biden\u2019s overall performance is up and down.<\/p>\n

\u201cIt almost seems like with every step forward there is a step back,\u201d he said.<\/p>\n

Maggie Kain, a Sanders supporter from Rhode Island, said Mr. Sanders has continued to garner a strong following because his backers want to make sure they have a voice in authoring the party platform at the Democratic National Convention.<\/p>\n

Ms. Kain said it shows how much Mr. Sanders\u2019 message has inspired activists across the country and provides a road map for Mr. Biden if he wants to generate more excitement about his campaign.<\/p>\n

\u201cIf he wants to get the people \u2014 the youth that are out in these Black Lives Matter marches \u2014 if he wants them to be as excited for him as they are for Bernie, it would benefit him greatly to be stronger on the issues they care about,\u201d Ms. Kain said.<\/p>\n

She said Mr. Biden is missing an opportunity by refusing to back full-blown marijuana legalization, which activists see as a way to move away from some of the racial bias in policing.<\/p>\n

\u201cI don\u2019t understand why the Democratic candidate doesn\u2019t understand which way the wind is blowing, and that makes me concerned about who he is listening to,\u201d she said. \u201cThat frustration is certainly felt among progressive activists.\u201d<\/p>\n

Yet Mr. Trump\u2019s name at the top of the Republican ticket will go a long way to paper over those frustrations, Ms. Kain said.<\/p>\n

\u201cI think people are very enthusiastic regardless of who they vote for in the primary because this message of voting against Trump is so big,\u201d she said.<\/p>\n

Mr. Biden holds an 8-percentage-point lead over Mr. Trump in national polls, according to the latest Real Clear Politics average of polls. He is also running ahead of the Republican in most battleground state polls.<\/p>\n

Stephen Farnsworth, a political science professor at the University of Mary Washington, said the fact that Mr. Biden isn\u2019t mopping up just about every vote at this point in the primary contests is not a surprise.<\/p>\n

\u201cActivists on both sides of the political divide often find themselves frustrated by the barriers to change that exist in national politics,\u201d he said. \u201cWhat you are seeing with the Democratic primaries in recent weeks is a preference being expressed by some Democratic votes that Biden move in a more liberal direction.\u201d<\/p>\n

It is not a bad omen for Mr. Biden, Mr. Farnsworth said.<\/p>\n

\u201cParty activists often find themselves with the choice of falling in line, or standing on the sidelines and helping the other party,\u201d he said. \u201cGenerally speaking, activists get in line come November.\u201d<\/p>\n