Rick Santorum was one of Mitt Romney's toughest foes during the GOP presidential race, but the former Pennsylvania senator plans to help Romney appeal to the party's conservative base when he addresses the Republican National Convention.
His speech Tuesday is expected to focus on welfare reform and charges that President Barack Obama wants to undermine welfare work requirements.
In an appearance on "CBS This Morning," Santorum called Obama's plan to issue waivers to states that want to test alternative welfare policies "a very, very serious assault" on welfare reform. White House officials have said Republicans are being misleading.
Santorum played a central role for Republicans when the 1996 welfare reform law was being debated.
He says his speech will convince voters that Obama's policies are leaving them behind.
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