Trump's GOP primary sweep: It's about jobs

U.S. Republican presidential candidate Donald Trump holds up a placard while he greets supporters after speaking during a campaign rally.

Donald Trump has steamrolled his GOP opponents with blunt promises to voters on a range of issues, from walling out immigrants to cutting taxes.

But one issue stands out in his five-state primary sweep Tuesday. It's about jobs.

"I'm going to bring jobs back from China, Mexico Japan, Vietnam," Trump declared in the South Carolina GOP debate in February. "They are taking our jobs. They are taking our wealth."

With almost all the votes tallied, Trump won every one of the 107 counties in the five states electing delegates to the GOP national convention in Cleveland. And, once again, he did best in counties with the highest unemployment rates, a CNBC analysis of county-level primary voting data shows.

The victory extends Trump's pattern of big wins in counties with jobless rates higher than the national average.

Of the 172 delegates up for grabs in GOP primaries in Connecticut, Delaware, Maryland, Pennsylvania and Rhode Island, Trump walked away with 109 of them, according to NBC News. Ohio Gov. John Kasichpicked up five and Texas Sen. Ted Cruz won only three.

Trump's performance all but fully derailed a last-ditch, apparently ineffective, "Stop Trump" deal between Kasich and Cruz to join forces to prevent the billionaire developer from winning the 1,237 delegates he needs to clinch the nomination on the first ballot.

As he has in the 46 states and territories that have voted so far, Trump turned in his strongest showing in Northeast counties that are still feeling the lingering effects of the massive job losses of the Great Recession. Some 74 of 107 counties in the five states that voted Tuesday have jobless rates above the national average of 5 percent, according to the latest data available.

To gauge how well Trump is faring with unemployed voters, CNBC has tracked GOP primary results in more than 2,200 counties in the states that have voted so far. (County-level data was not available for all states that have voted.) Of those counties, more than 1,400 had jobless rates above the national average of 5 percent.

Trump has won about three-fourths of those counties with higher-than-average unemployment. Cruz won about 20 percent of those counties, while Kasich won just 2 percent of them.

While Trump has been able to count on a big lead in the popular vote, the GOP's arcane rules of electing delegates — about which he has complained loudly — could work against him.

In three of the five Tuesday primaries (Maryland, Connecticut and Rhode Island), for example, the GOP rules allocate three delegates based on the winner in each Congressional district, with additional "at-large" statewide delegates. Tuesday's biggest single delegate prize was Pennsylvania, but those delegate counts are more problematic, because they're not all bound to the winning candidate.

Trump secured Pennsylvania's 17 statewide delegates — party members already chosen to go to Cleveland — who are bound to vote for the candidate who wins the most votes, but only on the first ballot.

The remaining 54 delegates were chosen from Pennsylvania's 18 congressional districts — but they're not bound on the first vote. That means none of those delegates are reliably in Trump's camp.

"You can go in there and vote for Trump, and vote for three delegates that are three votes against Trump," said Rep. Lou Barletta, R-Pa., a state co-chairman of Trump's campaign, told the Associated Press.

On the Democratic side, former Secretary of State Hillary Clintonextended her solid lead against Vermont Sen. Bernie Sanders, thanks in part to a big fundraising lead in Tuesday's five primary states. 

In those states, Clinton has raised nearly $15 million, almost three times Sanders, according to OpenSecrets.org.

Of the 384 delegates at stake in those five states, Clinton picked up 204 to bring here total to 2117 of the 2,382 needed to win her party's nomination in Philadelphia. Sanders picked up 146 to bring his total to 1330 — leaving him a very narrow path to a nomination.