In the early days of 2018, two leading Democratic groups commissioned a study on how best to engage and mobilize African-American voters. The impetus was the special Senate election in Alabama in which a groundswell of black voter turnout led to the shock election of Democrat Doug Jones.

The groups, Color of Change and Priorities USA, wanted to understand how that outcome had come to be and whether it could be duplicated nationally. What they discovered was that conventional wisdom about how Democrats should go about discussing Donald Trump was all wrong. Rather than galvanizing African-American voters, the president was depressing them. More respondents (39 percent) said they felt less motivated to vote since Trump’s election than those who said they felt motivated by the 2016 results (37 percent).

Those findings, including similar ones found in other surveys, had a profound impact on strategists and operatives, convincing them that the party needed to restructure its campaign messaging. Over the next nine months, the Democratic Party’s campaign committees and individual candidates began paying less attention to the president, even as he continued to demand the media spotlight and dominate the national political conversation. And when they did talk about Trump, those candidates were advised to actively try and de-emphasize him. The president was not a uniquely dangerous figure, the new framing went. Instead, he was something duller but equally fearsome: a Republican incumbent.

“We treat him so differently but that doesn’t lead to success,” said Matt Canter, a pollster for Global Strategy Group, the firm that conducted the survey on African-American millennials. “It does what he wants. When you treat him differently, it makes him different.”

The policy of conscious avoidance of Trump proved successful for Democrats in the 2018 elections, with the party winning 40 seats in the House and stemming its losses in a historically bad Senate landscape. Now, as Democrats are gearing up for the 2020 elections, some of its party’s potential presidential candidates are trying it again.

In announcing the creation of an exploratory committee to grease the wheels for a White House run, Sen. Elizabeth Warren (D-MA) put out a four-and-a-half minute video that never mentioned Trump’s name. Her counterpart in the Senate, Kamala Harris (D-CA), released a book this week that spends little time actually going after Trump. Instead, it recounts her attendance at his inauguration, her feelings when he was elected and even refers to the president as "that man," while describing how she learned of the presidential results in 2016. And in an appearance on MSNBC’s Morning Joe this Friday, Harris was explicit in how she would approach the president should she choose to formally launch a White House bid.

“My focus, if I were going to run, it would not be Donald Trump,” she said.

There are a variety of reasons why Harris, Warren and—in all likelihood—many others who jump into the 2020 campaign would choose not to focus their attention on Trump. As a purely practical matter, strategists note, these candidates are entering a Democratic primary, in which their primary goals will be to introduce themselves to voters, showcase their progressive bona fides and distinguish their resumes from the rest of the field. Trump is largely irrelevant to all of those tasks.

“ People assume all Dems are against Trump. So I don’t think there was much utility in going after him. ” — Celinda Lake, a longtime Democratic Party pollster

But pollsters and strategists in the party say that a larger strategic reasoning is also at play. Put simply, no prospective candidate actually has to show that they are against Trump because voters already assume so.

“We studied it,” said Celinda Lake, a longtime party pollster. “People assume all Dems are against Trump. So I don’t think there was much utility in going after him.”

This was another major takeaway that Democratic pollsters drew from the 2018 election. Exit poll data showed that a good chunk of voters (38 percent) cited opposing the president as a reason they voted. But those voters did so in spite of the fact that Democrats were not talking about Trump directly not because they were being encouraged to make protest votes.

Much of this will likely change as the 2020 election progresses, strategists say. At some juncture, Democratic voters are going to be making decisions on which candidate to support based largely on who they think will be best positioned to beat the president. And, of course, when the general election begins, it will be incumbent on the Democratic candidate to engage the president forcefully and directly. The policy of strategic Trump avoidance will come to an end by necessity.

But even when that happens, the hope among top operatives is that Trump will be tackled in subtler ways than in the past. One of the main lessons that has been drawn from the 2016 election was that Hillary Clinton’s campaign erred by framing Trump as a uniquely unqualified and unacceptable candidate for the presidency. Doing so created real and artificial distance between Trump and down-ballot Republicans (distance that those Republicans welcomed). In that January 2018 survey conducted among African-American millennials, only 44 percent of respondents actually believed that most Republicans supported Trump.

But the framing was also counterproductive in other ways, strategists and even Clinton veterans concede, as it reinforced Trump’s desired claim that he was, indeed, unique and would shake up politics accordingly.

“There was a thinking that many of the comments he made and policy positions he staked out were inherently disqualifying in themselves and that simply reminding voters of what he said and asking the country if this is the person they wanted to elect as their leader, that that question would answer itself,” said Brian Fallon, Clinton’s 2016 chief spokesman. “Part of that strategy was trying to drive a wedge between those who otherwise would vote Republican but wouldn’t vote for Trump... That did happen. It just didn’t happen at the order of magnitude she needed.”

Few Democrats anticipate a redux of that 2016 argument in 2020, in part because of lessons learned but also because it would now ring hollow. Trump has spent two years in the Oval Office, during which time he has signed into law and championed virtually all of the Republican Party’s domestic agenda. He is no longer sui generis among political figures. He’s now the leader of a political party. That brings with it some advantages but also vulnerabilities.

“In 2016, Hillary had a really hard time because she was a third term, and because she’d been around she didn’t communicate change. She was trying to make Donald Trump a uniquely bad candidate and, in the end, voters did a Hail Mary for change,” said Lake. “People weren’t that sensitive to it. Now, in 2020, it will be entirely different. You can run on his record and where things are at. He’s the incumbent.”