I'm pointing out that the Presidential election can be won without winning a majority of the white vote. Democrats are already reaching out to white voters. It is unlikely that Democrats will win the majority of the white vote in 2020. If Democrats only rely on the white vote, they will not win the Presidency. 
 

Edit to add

Impact of black voter turnout 

Among the many factors that contributed to Hillary Clinton’s shocking defeat in 2016, one pretty much everyone agrees upon (though not necessarily about its relative significance) is a falloff in African-American turnout relative to 2012. The numbers are clear, as Politico reported in 2017:

The Census’ Current Population Survey, released Wednesday, shows 65 percent of white citizens cast ballots in last year’s presidential election, up from 64 percent four years earlier.

 

But the turnout rate among African-American citizens tumbled sharply, the survey shows. Only 59 percent of black citizens voted in 2016, down from 66 percent in 2012 and 65 percent in 2008.

Those national numbers may underestimate the size and impact of lower black turnout in individual battleground states, as Osita Nwanevu observed:

Crucially, the drop in black turnout was even sharper in states where the margin of victory was less than 10 points than it was nationally — in those battleground states, black turnout dropped 5.3 points. In two critical states that swung to Trump — Michigan and Wisconsin — black turnout dropped by just more than 12 points. Declines were less dramatic but significant in other swing states Trump carried: Ohio (down 7.5 points), Florida (4.2), and Pennsylvania (2.1). White turnout declined modestly in each of those swing states but Florida and Pennsylvania, where it increased by 3.5 points and 5.2 points respectively. Clinton lost each of those swing states but Ohio by a margin of less than 2 points.

Conversely, a return to higher black turnout could be a key element in toppling Trump next year. In a major study from the Center for American Progress, Ruy Teixeira and John Halpin project that natural demographic trends in the last four years plus a return to 2012 levels of African-American voting would flip four states — Michigan, North Carolina, Pennsylvania, and Wisconsin — and give Democrats a 294-244 majority in the Electoral College. And even if black voting turnout doesn’t quite hit those levels, in many states even marginal changes in turnout and Democratic vote-share could make the difference in a close race.

https://nymag.com/intelligencer/2019/11/how-can-democrats-get-the-black-turnout-they-need-in-2020.html