"The nomination is not the only aspect of what politics is about. What politics is about is trying to do well by the middle class and by working families. That is what I am struggling to do," Sanders told CNN's Wolf Blitzer in an interview.
The Vermont senator has lost the race as Clinton claimed enough delegates to become the presumptive Democratic nominee -- but he hasn't dropped out, keeping his Secret Service protection
and pledging to continue on until the Democratic National Convention in Philadelphia later this month.
He pointed to a Democratic platform meeting in Orlando on Friday and Saturday as one of his major areas of focus, saying he wants stronger language opposing the Trans-Pacific Partnership, a 12-country trade deal negotiated by President Barack Obama's administration, included.
"The TPP should not get to the floor of the U.S. House or the U.S. Senate," he said, adding, "It's not a demand, it's something that we are fighting for."
Sanders added that he doesn't want the TPP to receive a vote in a lame-duck session before the next president is inaugurated. He also called for a carbon tax, a ban on fracking and a federally-mandated $15-an-hour minimum wage. He said those will be his priorities in the platform fight.
"The goal of this whole effort -- it's not a game and it's not silly business," Sanders said. "This is to create public policy."
He lauded Clinton's college affordability proposal she rolled out in Atlantic City, New Jersey, on Wednesday, which extends free tuition at in-state public universities to families of four making up to $125,000.
"That is a revolutionary breakthrough for the middle class and the working class of this country," Sanders said.
And, Sanders said, he is working with Clinton's campaign on further proposals that would blend the ideas both have advocated. "We are working on other ideas, as well," he said.
Sanders dismissed reports that House Democrats had booed him
in a meeting earlier Wednesday when he hadn't endorsed Clinton.
"I don't know if people were discontented, but I think most of the people were very friendly and very appreciative," he said.
And while he kept up his criticism of Clinton -- pointing out that she voted for the war in Iraq while he opposed it -- he wouldn't attack her for it.
"I'm not going to be sitting here analyzing Hillary Clinton or anybody else," he said.