Trump flung criticism at politicians spanning the spectrum from presidential primary opponents Jeb Bush and Ben Carson to the Democratic front-runner Hillary Clinton and the man he hopes to succeed, President Barack Obama, in an interview with CNN's Jake Tapper that aired Sunday on "State of the Union."  And he lamented the House Select Committee on Benghazi's questioning of Clinton, a hearing he called "very partisan" that "hurts both parties" and "hurts the country."  "The level of hatred between Republicans and Democrats was unbelievable. The level of -- I've never seen anything like it," Trump said. "I'm going to unify. This country is totally divided. Barack Obama has divided this country unbelievably. And it's all, it's all hatred, what can I tell you. I've never seen anything like it...I've gotten along with Democrats and I've gotten along with Republicans. And I said, that's a good thing."  Tapper asked Trump if his presidency would result in an era of bipartisanship.  "I absolutely think so," he said, adding, "I will be a great unifier for our country."  RELATED: Trump says world would be better with dictators still in power  While Clinton has taken flak for what she's described as a tongue-in-cheek statement that the enemies she's most proud of having are Republicans, Trump said he doesn't consider Clinton an enemy -- simply, "an opponent."  Still, for all the talk of bipartisanship and unity, Trump did not pull punches as he vigorously took on his opponents.  Trump hit Bush, the former governor of Florida, and Carson, a retired neurosurgeon, with the same line of attack -- one he has frequently used against Bush, but has only just begun using against Carson, whose reserved and calm tone strongly contrasts with Trump's brash appeal.  "(Bush is) a low-energy person. By the way, Ben Carson is a very low-energy person. We need high-energy people," Trump told Tapper. "I think Ben Carson is a very low-energy person. Actually, I think Ben Carson is lower energy than Jeb, if you want to know the truth. We need strong energy."  RELATED: Trump's dipping poll numbers in Iowa  Trump also knocked both Bush and Carson for the support they receive from super PACs, groups that can take in unlimited amounts of money.  The developer dinged super PACs as a "big fat scam" and a "disaster" in the "State of the Union" interview, a line of criticism that he brought out more arduously than ever this weekend, just days after the super PAC backing his candidacy shuttered its operation after the group's ties to the campaign drew scrutiny last week.  But Trump suggested that he may turn his sights away from Bush and toward Carson.  That's because Carson is now the man to beat in Iowa, stealing first place from Trump (who was relegated to second place) in two polls released Thursday and Friday.  "The thing with Ben is he's got a very good PAC, and he's got people running his PAC, and in my opinion, he's got people all over Iowa from his PAC, and they are running -- Ben doesn't even go to Iowa that much. And he's doing well in Iowa?" Trump said. "I did talk about Jeb because I thought Jeb was going to be the front-runner. Obviously, he's no longer the front-runner. I probably won't talk about him so much anymore."  In a previously released segment of this interview, Trump also knocked Carson for his stances on immigration and questioned his capabilities as a negotiator.  Trump tied in his "low-energy" attacks with what he dubbed the "medieval times" that the world is currently living in -- saying that as ISIS beheads people, the U.S. needs a strong leader.  But as to whether he would approve a special forces operation to rescue hostages being held by ISIS -- similar to the one that resulted in the death of an American soldier this week-- Trump demurred.  "I think I might, but I'd have to look at the situation," Trump said.  Pushed further to explain what the Trump doctrine would be in such situations, Trump explained that it "is very simple."  "It's strength. It's strength. Nobody is going to mess with us. Our military is going to be made much stronger," Trump said.
Donald Trump believes he would "absolutely" be a force for bipartisanship, but in an interview this weekend neither Republicans nor Democrats escaped a barrage of attacks from the GOP presidential candidate.