WASHINGTON/BETHESDA, Md. (Reuters) - Wealthy, well-educated voters helped carry Republican presidential front-runner Donald Trump to victory in this week’s East Coast primaries, a demographic the famously blunt-spoken billionaire had struggled to attract in the past.

U.S. Republican Presidential candidate Donald Trump arrives to speak at a campaign event in Indianapolis, Indiana, United States, April 27, 2016. REUTERS/Jim Young

His sweep of Pennsylvania, Maryland, Delaware, Connecticut and Rhode Island on Tuesday included wins in some of the richest and best-educated counties in the country - like Fairfield County, Connecticut, and Newport County, Rhode Island - and added to victories in his more traditional strongholds of white working-class neighborhoods.

Exit polls from Connecticut, Pennsylvania and Maryland showed Trump winning about half of Republican voters with college degrees, and over half of Republican voters making more than $100,000 a year.

“On its face, it is hard to believe he’d be improving with a demographic group that has been so averse to his style, his denigrating language,” said Randall Miller, a professor of American politics at Saint Joseph’s University in Pennsylvania.

“But I think people may have gotten used to Trump, he’s not as outrageous as he used to be,” he said, adding that familiarity with the businessman’s brand in the Northeast may also have helped him.

Still, the five states could be an uphill battle for Republicans in the Nov. 8 presidential election. The last Republican presidential nominee to win any of them was George H.W. Bush in 1988.

The challenge for the New York billionaire could be to replicate Tuesday’s performance in other parts of the country as he seeks to lock down his party’s nomination, with 10 state contests remaining.

Nationally, likely voters with a college degree have become increasingly critical of Trump in recent months, according to Reuters/Ipsos polling. He is also increasingly unpopular with those who make more than $100,000 a year.

But with Trump far ahead of his rivals, U.S. Senator Ted Cruz of Texas and Ohio Governor John Kasich, in the race for the presidential nomination, Miller said Republican voters of all stripes may become more resigned to voting for Trump.

“I think it is possible he replicates this.”

ANTI-ESTABLISHMENT

Trump has historically done well in areas where the collapse of important local industries has put stress on working families - propelling his popularity among poorer white voters drawn to his rhetoric about inept government and failed international trade deals.

That narrative persisted in Tuesday’s contests. Trump took more than 63 percent of the vote in Forest County, Pennsylvania, where the median family income among whites, at $45,000, is the lowest in the state. But he also got more than 46 percent of the vote in Chester County, Pennsylvania, where median income for whites is the highest in the state, at $108,000.

A Franklin and Marshall College voter survey released last week showed Trump’s message of disaffection had sunk in across the state. Just under 40 percent of voters cited “government, politicians” as the most important problem facing Pennsylvania, with “unemployment, personal finances” ranked a distant second at 14 percent.

In the affluent Maryland suburbs of Montgomery and Howard counties, where more than 60 percent of whites hold college degrees, Trump claimed a smaller 40 percent share of the Republican vote. It was still enough for a first-place finish over Cruz and Kasich.

Fred Stubbs, 72, a retired accountant from Potomac, Maryland, said he voted for Trump on Tuesday because he believed the real estate mogul would improve the country’s standing in the world. He added that when he traveled to New York, he regularly dined in restaurants in buildings owned by Trump.

“I’ve always admired him as a businessman,” Stubbs said.