And despite the internal poll data, Trump retains the power of incumbency, with Election Day 17 months away and Democrats' first presidential nominating contests in eight months.
At this same point in the 2016 election cycle, Democrat candidate Hillary Clinton was ahead of Trump by 17 points.
The poll leak fallout comes as Trump gets ready to launch his re-election bid in Orlando Tuesday night.
Adam Geller, who was also a pollster for the Trump campaign in 2016, was another who was let go, according to another Republican familiar with the situation. In three of those states - Wisconsin, Pennsylvania and Florida - Biden's leads sit outside the poll's margin of error, according to NBC. But Trump's campaign manager, Brad Parscale, later confirmed that the results were indeed from a poll conducted by the campaign in March, and on Friday, ABC News published the results. Lloyd is president and CEO of The Polling Company, the former firm of White House senior counselor Kellyanne Conway.
The president last week called the polls in the news reports "phony" and said the campaign's internal polling is "unbelievably strong".
"That 50-50 number encapsulates how divisive Trump is", said James Henson, who runs the Texas Politics Project at the University of Texas at Austin and co-directs the poll.
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An Internet survey by the University of Texas and Texas Tribune revealed Biden with 23 percent support from Democrat primary voters.
Among voters who want a more progressive direction, Biden is in much tighter competition with Warren and Senator Bernie Sanders of Vermont, the poll found.
"I think we can win in Pennsylvania, Wisconsin and MI and some of the other battleground states", Sanders said on "Fox News Sunday".
The poll looked at 18 states that will influence the Democratic contest through Super Tuesday, including the bellwether states of Iowa, New Hampshire, and SC.
The negative response about Trump was up 3 percentage points from a poll conducted in late April and early May.
Democrats begin more earnestly winnowing down their field of almost two dozen candidates when they hold successive nights of televised debates on June 26 and 27. They show former Vice President Joe Biden beating Trump 49 percent to 39 percent.
The CBS study translated vote choice into delegates - which showed Biden having the edge necessary to lock up the nomination at next year's national convention.