Washington: Democratic presidential hopefuls Hillary Clinton and Bernie Sanders are arch rivals but both leaders are trying to make their case using Republican frontrunner Donald trump.

Clinton and Sanders clearly didn't pay much attention to each other on Sunday night during a town hall aired live on CNN but they did not miss a chance to lash out against Trump. Both accused the billionaire businessman of creating a culture of violence on the campaign trail.

"I'm not going to spill the beans right now, but suffice it to say, there are many arguments we could use against him," Clinton said.

Here are six takeaways from the Democratic town hall in Columbus:

'Pathological liar' and 'political arson'

Clinton and Sanders did not mince mince words when attacking Trump. The two accused Trump of responsible for a string of violent incidents at his campaign events in recent days.

Sanders attacked Trump calling him a "pathological liar." He cited a 78-year-old who now faces criminal charges after he sucker-punched a protester who was being escorted out of a Trump event in Fayetteville, North Carolina and Trump's comments Sunday that he will want to foot the legal bills of the man. "He's going to pay the legal fees of somebody who committed a terrible act of violence. What that means is Donald Trump is literally inciting violence in his supporters," Sanders said.

Clinton accused Trump of "political arson", saying: "He has lit the fire and then he throws his hands up and claims that he shouldn't be held responsible. He has been incredibly bigoted towards so many groups. You don't make America great by tearing down everything that made America great."

Strategy against Trump

Both Democrats tried to best to claim that they are the one best suited to run against Trump in November. Playing up her tenure as secretary of state, Clinton argued that Trump's incendiary rhetoric undermines "our standing in the world." "I'm having foreign leaders ask if they can endorse me and stop Donald Trump," she said.

On the other hand, Sanders pointed to polls that show him leading Trump head-to-head nationally. And he said his ability to bring young people into the political process can counteract the GOP's ability to "win when voter turnout is low." "The American public is not going to elect a president ... insulting virtually everybody who is not like Donald Trump. Thank God most people are not like Donald Trump," he said.

Clinton on the death penalty

The night's most important moment came when Ricky Jackson, a black man who remained behind bars for 39 years for a murder he hadn't committed, asked Clinton to clear her stance on the death penalty. "I would breathe a sigh of relief if either the courts or the states themselves began to eliminate the death penalty," Clinton said.

Then, turning to Jackson, Clinton said: "What happened to you is a travesty and I can't even imagine what you went through and how terrible those days and nights must have been for all those years. And I know that all of us are so regretful that you or any person has to go through what you did. And I hope that now that you are standing here before us that you will have whatever path in life you choose going forward."

Clinton and coal miners

During her comments about creating jobs in rural, predominantly white portions of the United States, Clinton said that Republicans will be more than happy to run again and again. The clip that will make it into attack ads: "We're going to put a lot of coal miners and coal companies out of business."

"We're going to make it clear that we don't want to forget those people. Those people labored in those mines for generations, losing their health - often losing their lives - to turn on our lights and power our factories. Now we've got to move away from coal and all the other fossil fuels, but I don't want to move away from the people who did the best they could to produce the energy which we relied on," she added.

Sanders double-dips on trade

As Sanders talked free trade, he targeted two front-runners simultaneously. "Trade is a positive thing, nobody is talking about building a wall around the United States," Sanders said, to some laughs from the audience. "I beg your pardon, there is one guy .... Let me rephrase it: No rational person is talking about it."

"Of course we're going to do trade," Sanders said. "But trade policies have got to be policies that work for the people of our country."

Friends and family

During a debate in Miami last week, Clinton said she is "not a natural politician" like Bill Clinton or Barack Obama and on Sunday, she said that soaring rhetoric will never be her strong suit. "I am much better when I actually have a job to do," Clinton said, "rather than trying to get the job."