SIOUX FALLS, S.D. -

Weeks before the November election, most national polls projected Hillary Clinton winning the presidential election. As we know, that wasn't the case. Still, more than a week later, many are wondering how so many could get it wrong? KDLT's Jill Johnson sat down with a local pollster on how they did in South Dakota and the process.

Paul Nielson and his brother Mark got into polling at the state and local level 6 years ago.

"We just decided there wasn't a lot of polling going on," said Nielson. "We put together a program for it, we contacted a local vendor for phone calls and we jumped in."

Nielson Brothers Polling takes a sample of the population; around 450 to 600 people. They come up objective questions and calls are sent out to likely voters.
    
Nielson said, "My brother takes that data, organizes it, then weights the data according to the population that we've been trying to reach and we go from there."

This year they only polled up until the first and second of November, because there wasn't much suspense.

"It was more of a question of how much than who was going to win," Nielson said.>[Duration:0:04]

They figure the margin of error to be 4 or 5 percent. In their most recent survey, Nielson Brothers predicted Trump winning South Dakota. They were off by about 10 percent and Clinton by 4 percent. In the U.S. Senate race, they had John Thune winning 53 percent of the vote. He won with 72. They had Kristi Noem winning 51 percent in the U.S. House race. She came away with 64. He says they underestimated the number of Republicans who came out and overestimated the Democrats.

"Tennessee and South Dakota, who have a very high Republican population, they outdid their polls generally. In fact, the greater Republican party population in the state, the greater they outdid their polls this year," said Nielson.

Nielson says a lot of the national polls got specific states wrong. There were also more undecided voters this year, and many broke for Trump. Nielson says nationally we need to take a look at who didn't vote. He says Trump and Clinton received less votes than their party candidates in the 2012 election.

Nielson says people want to know information immediately and in politics there is no break. Potential candidates are already talking to the Nielson Brothers about the South Dakota Governors race.

Based on their recent polling, Nielson believes many will look to initiatives to get things done in the state. He says a lot of the ballot measures were divided between Republicans and Democrats. Of the seven measures NBP polled on, they got 6 right.