But the DSCC chairmanship is one of the most prominently partisan positions a senator can hold on Capitol Hill, as it requires the lawmaker to raise millions to support Democratic candidates in election fights that can get nasty.

The Denver Post report reveals Bennet was concerned that accepting the position would undermine his ability to continue that work with Republicans. He sought, and received, "assurances from all over Capitol Hill" that he would be able to continue his bipartisan work before accepting the position, according to the Post.

And Bennet indicated he plans to continue negotiating with his Republican colleagues on issues, despite the long hours he'll have to spend traveling and fundraising over the next two years.

"We're going to have to figure out how to make it work with the other responsibilities I have," he said.