- Donald Trump posted on Truth Social Friday about Robert F. Kennedy Jr.
- Trump called the third-party candidate a "Democrat 'Plant'" and "Radical Left Liberal."
- The diatribe comes as polling shows RFK Jr.'s run could siphon votes away from Trump.
Donald Trump will likely face a second contest against Joe Biden in the upcoming election, but the former president has another candidate currently in his crosshairs.
On Friday evening, Trump took to Truth Social to attack Robert F. Kennedy Jr., an independent candidate running a long shot presidential campaign.
"RFK Jr. is a Democrat 'Plant,' a Radical Left Liberal who's been put in place in order to help Crooked Joe Biden," Trump alleged in his post.
At the moment, six months before the election, Trump appears to have a razor-thin .8% lead in polls against Biden, according to national polling averages compiled by FiveThirtyEight. Polling for Kennedy shows he has 10.2% overall support, while Trump and Biden have 41.7% and 40.9%, respectively.
A Bloomberg News/Morning Consult poll also showed Trump as the favorite over Biden in six of seven battleground states, which is a key metric used to determine who could win the election.
So why is Trump harping over a longshot independent candidate?
Evan Siegfried, a former GOP strategist and crisis communications specialist, told Business Insider that Trump's diatribe is expected, considering another recent poll showing that Kennedy could actually hurt Trump in the election.
An NBC News poll published this month showed that Kennedy could siphon votes away from Trump, giving Biden a 2-point lead if the choices included all candidates — not just Biden and Trump.
"Honestly, this is not a surprise because in the last few weeks, polling has started to show that Kennedy takes away more from Trump than it does for Biden," Siegfried told BI. "He's clearly turned on RFK Jr. simply because he takes away from battleground states."
Trump's Friday attack is a notable shift in tone on Kennedy.
On April 5, The New York Times reported that Trump considered the Democrat scion as a possible running mate, according to two sources familiar with the conversations.
"I like Trump-Kennedy," Trump told one person, according to the report. "I like the way that sounds."
Kennedy dismissed the idea and told the Times it was "not a course I would consider."
A spokesperson for the Kennedy campaign declined to comment but pointed to an X post from the candidate on April 15.
"President Trump calls me an ultra-left radical. I'm soooo liberal that his emissaries asked me to be his VP," he wrote. "I respectfully declined the offer."
Siegfried told BI that Trump would love to establish a "dynasty" and one of the best ways to do that would be to attach oneself to the Kennedy name.
But the consideration was likely a passing thought the former president was "musing on," Siegfried said, adding that even Trump's advisors probably knew it wouldn't be a reality.
The Trump campaign did not immediately respond to a request for comment from Business Insider.