I think liberals focus on policy issues and progressives focus on social justice issues. These are not exclusive of each other, policy can be used to better society, and social justice can be brought about by policy. But liberal policy doesn't necessarily serve social justice - for instance, NAFTA and the repeal of Glass-Steagal both happened under liberal President Clinton's administration. True progressives could probably not make it in American politics - almost certainly not on the Democratic ticket. We are viewed as too extreme. I think some modern progressives might include Michael Moore and Amy Goodman. The closest we get in Congress are maybe Elizabeth Warren (we'll see how she does inside the beltway) and Alan Grayson.