Hillary Clinton and Donald Trump

Republican Donald Trump pulled even with Democratic rival Hillary Clinton in a Reuters/Ipsos opinion poll released on Wednesday, in a dramatic early sign that the Nov. 8 presidential election might be more hotly contested than first thought.

While much can change in the six months until the election, the results of the online survey are a red flag for the Clinton campaign that the billionaire’s unorthodox bid for the White House cannot be brushed aside.

Trump’s numbers surged after he effectively won the Republican nomination last week by knocking out his two remaining rivals, according to the poll.

The national survey found 41 percent of likely voters supporting Clinton and 40 percent backing Trump, with 19 percent undecided. The survey of 1,289 people was conducted over five days and has a credibility interval of 3 percentage points.

“Very happy to see these numbers,” Trump said in a written comment to Reuters. “Good direction.” A spokesman for Clinton’s campaign did not respond to requests for comment on the poll.

A Reuters/Ipsos survey conducted in the five days to May 4 had the former secretary of state at 48 percent and the New York magnate at 35 percent.

Republican strategist Dave Carney said the Reuters/Ipsos poll showed the vulnerability of Clinton, who is still battling U.S. Senator from Vermont Bernie Sanders for the Democratic nomination.

“She has been in the public eye for decades, served in high office, and now she’s in a dead heat with Trump, in a race that everyone thought she would win easily,” said Carney, who has been critical of Trump. “Everyone thought it would be a romp.”

REPUBLICAN RELUCTANCE

Trump has his own problems, though. He is struggling to bring some senior Republicans behind his campaign after primary election battles in which his fiery rhetoric rankled party elites.

Several Republican leaders — including House of Representatives Speaker Paul Ryan — are withholding their support.

“After a tough primary, that’s going to take some effort,” Ryan said about unifying the party. “We are committed to putting that effort in.”

The former reality TV star will face pressure to tone down his rhetoric and clarify his policy positions when he visits Republican lawmakers, including Ryan, on Thursday.