Robert F. Kennedy Jr. suspending his campaign and endorsing former President Donald Trump for President of the United States is a nightmare scenario for Vice President Kamala Harris.

The independent candidate was only polling at around 5 percent nationwide but in a tight contest between the two main candidates that minor percentage could be what decides the presidency, The New York Post reported.

“Most of Kennedy’s left-leaning support had already dispersed to Harris,” Cook Political Report senior editor and elections analyst Dave Wasserman said to The Post. “So this could represent a meaningful benefit for Trump.”

“We’re talking probably a fraction of a point in our survey from August in battleground states,” he said. “Forty-six percent of RFK supporters went with Trump in a two-way race, 26% went with Harris and Kennedy’s support had collapsed from 8% to 5% nationally.”

“Campaigns would spend hundreds of millions of dollars for a fraction of a point given how tight the margins are in these battleground states,” he said as he referenced the tiny margins in 2020, particularly in Arizona and Georgia.

“RFKs endorsement won’t move all his supporters to Trump,” he said. “We’re in a very volatile environment right now and it could remain that way through the election.”

Chris Lane, a pollster for Cygnal, said that “among swing voters who will ultimately decide this election, 16% indicated they were going to vote for RFK.”

“With margins in battleground states being razor-thin, that 16% could represent the difference between winning and losing a state,” he said. “If RFK encourages his supporters to vote for Trump, it could have a massive impact and change the calculus for both Trump and Harris, especially in battleground states.”

“Add in the fact that those 16% are more center-right than anything, and will ultimately add to Trump’s ballot share,” he said. “Our data shows 4:1, these swing voters were more likely to call themselves conservatives than liberals.”

And even anti-Trump pollster Frank Luntz said the RFK endorsement could decide the election.

“It’s probably worth about 1% for Trump and that 1% could be everything if it’s in the swing states. In the end, the reason why Kennedy was drawing 10, 12, even as high as 14% is because he was taking votes away from Joe Biden. Joe Biden’s gone. Kamala Harris has replaced him, and [RFK’s] vote collapsed down to about 4 or 5% and what’s left is a Trump vote,” the pollster said when he appeared on NewsNation after the endorsement and spoke to host Leland Vittert.

“Some of them are simply not going to participate in November. Roughly two to one, the ones who are remaining will vote for Trump over Harris and that’s worth a single percent and that single percent can make the difference in Pennsylvania, Michigan, and Wisconsin,” added Luntz.

He also attacked the media for its response to the RFK endorsement.

“If he had endorsed Harris, I do think he would be regarded as a hero, but because he endorsed Trump, the people who are communicating that are not giving him the credit that he deserves, and I think we have to be careful in the last 73 days of this election campaign to understand the motivations of the people providing us information,” said Luntz.

Scott Rasmussen, who founded Rasmussen Reports, said that recent polling shows the former president getting a “slight” benefit.

“RMG Research polling for the Napolitan Institute this week showed Harris up 2 points 48% to 46% with RFK in the mix at 3%. When we pushed the RFK voters to make a choice, the race was tied at 49% at 49%,” the pollster said.

“While that suggests a slight boost for Trump, there are many other things that could have a bigger impact on the race — especially the debate and economic trends,” he said.

“However, in recent years, we’ve had the Electoral College winner determined by a relative handful of votes in a few swing states,” he said. “If that happens again, any blip in support from RFK voters could be important.”