MINNEAPOLIS — In yet another sign of the divisive nature of the 2016 race to the White House, in which both parties are struggling to unite behind their presumptive nominees, a popular liberal website wants to cut down on attacks on Hillary Clinton by Bernie Sanders supporters.

Markos Moulitsas, the founder and editor-in-chief of the Daily Kos, a liberal blogging site which supports the Democratic Party, told the site’s users in March that the site would soon be transitioning to “General Election footing.”

According to his blog post, this meant bloggers would be banned from making “attacks on Hillary Clinton using right-wing tropes of sources.”

“She’s had 30 years of bullshit flung at her from the Right, there’s no need to have Daily Kos give them an assist,” Moulitsas wrote.

“Constructive criticism from the Left is allowed,” he added, but cautioned that “if you’re resorting to cheap sloganeering like ‘oligarch’ or ‘warmonger’ or ‘neocon’, you might want to reframe your argument in a more substantive, issue-focused and constructive matter.”

Users are also banned from advocating for Jill Stein or other third-party candidates. “If that’s how you feel, but have other places in which you can be constructive on the site, then keep your presidential feelings to yourself.”

“Those of us who care about our country and it’s future are focused on victory,” he continued. “If you aren’t, then it’s a big internet, I suggest you find more hospitable grounds for your huffing, puffing, and stomping of feet.”

Founded in 2002, Daily Kos remains an important voice in the online liberal “blogosphere.” Quantcast, which measures Internet traffic, estimates that the site had over 8 million visitors in the last month. But the site has also faced its share of controversy, including accusations of banning unpopular viewpoints.

In his March announcement, Moulitsas acknowledged the disappointment many liberals feel in this year’s presidential race, but urged his fellow Democrats to focus on local battles and other reforms, such as eliminating superdelegates and removing Debbie Wasserman Schultz, the Democratic Party chair, from office.

Numerous writers reacted to the move with anger and sharp criticism, among them Ben Norton, a politics staff writer at Salon. In a March 9 post on his personal blog, Norton, who claimed to have been previously banned from the site for criticizing Israel, called the policy “draconian.”

“[I]n the mind of Daily Kos’ overlord, calling an oligarch an oligarch, a warmonger a warmonger, or a neocon a neocon — if that oligarch, warmonger, or neocon happens to be a Democrat (and many Democrats fall neatly into all three categories) — is just right-wing hatred, and will presumably lead to an immediate ban,” he wrote.

Jason Spurlock defended the move in a March 5 post on Daily Kos. The policy, he argued, wasn’t meant to shut down debate, but rather to ensure civility:

“That is the difference between debating a issue and using a issue to bash someone over the head with who doesn’t agree with you.

Personally I rather us still have logical debates just not the flame wars or the I am right and you are wrong. If we can still talk about things like gentleman and ladies then there should be no problem discussing the issues we used to do that a lot on dailykos without insulting each other for who we support.”

At least one user has been banned since the policy went into effect — Sean Robertson, a blogger at caucus99percent, claimed he was kicked off of the site last month after reporting on rumors that a Clinton social media staffer quit after being directed to attack Sanders. Although the story was later called into question, employees of Correct the Record, a Super PAC linked to Clinton, are paid to criticize her opponents on social media.

Many political analysts see the 2016 election as an especially contentious race, with scores of Democrats and Republicans rebelling against the presumptive presidential nominees for their respective parties. A May 22 poll by ABC News and The Washington Post found that a majority of voters hold unfavorable views of both Clinton and Donald Trump. And a May 12 poll by an independent research firm, Data Targeting, found that although Clinton is likely to win in November, 55 percent of Americans want the option to vote for a third party.