Driving the news: According to a new NBCNews poll, 70% of Americans believe Biden should not run for re-election, with 51% of Democrats saying that. (The poll was taken before Biden officially announced his re-election bid).
Meanwhile, 60% of Americans, including a third of Republicans, say Trump, 76, should not run for president.
Half of those who say Biden, 80, should not run again cite his age as a "major" reason.
Still, Democratic and Republican voters still say they will vote for the former and current president in the general election.
88% of Democratic voters say they’d definitely or probably vote for Biden.
Almost half, 46%, of Republican primary voters would support Trump as their first choice in what is expected to be a crowded field, per the poll.
The big picture: Biden sees Trump as a threat to America and as the primary reason to run for president and build his campaign around, Axios' Hans Nichols reports.
Methodology: The NBC News poll was conducted April 14-18 of 1,000 adults — including 861 reached by cell phone — and it has an overall margin of error of ±3.1 percentage points.
The margin of error for the poll’s 800 registered voters is ±3.46 percentage points, and the margin of error among the 292 Republican primary voters is ±5.99 percentage points.