While Brown ran for what he dubbed the "people's seat," the Republican has said that he admired Kennedy, even when he disagreed with him.
In a commencement address he delivered last year at Lasell College in Newton, Mass., Brown explained his decision to keep a picture of Kennedy on his office mantel.
"It reminds me not only of somebody I liked and respected, but also of a promise I made to my friends back home to work with people of goodwill wherever I find them," Brown said.
Brown's decision to cast the debate over contraception coverage as an issue of religious freedom in a state with a significant Catholic population could also be an attempt to win over voters uneasy with what they see as an overreach of government authority, regardless of whether they use contraception themselves.
Neither Brown nor Warren is Catholic.
It's not the first time Brown has pushed for a religious exemption.
As a member of the Massachusetts House in 2002, Brown supported an amendment that would have created an exemption for larger church-affiliated institutions like hospitals and universities to a bill requiring employers who purchase insurance plans in Massachusetts pay for contraceptives.
The amendment was defeated and Brown ultimately voted in favor of the main bill, which did include an exemption for smaller religious employers that meet the definition of a church or "church-controlled organization."
Brown's campaign said he wasn't willing to scuttle the entire bill over the broader exemption.
Brown, the only Republican in Massachusetts' congressional delegation, is facing a tough re-election campaign.
Although one recent poll showed him with a 9 percentage point lead over Warren, other polls have had the two locked in a tight race. Brown has cast himself as the "underdog" in a state where voters generally favor Democrats.
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