We need to strip government of unneeded power and put ourselves back into proper Constitutional governance. The problem is, progressives need the power of the Police State to enforce their progressive policies. But they are the first ones that complain about the police state.
First of all, don't conflate the Democrats with progressives, we don't have a progressive party in the US. Second, US conservatives are just as (or more) authoritarian as it's so-called liberals. Don't get me wrong, I'm no longer a fan of Obama but Romney would have been no better. Second, look at all the votes for the Patriot Act in 2001 and 2006: the overwhelming majority of nay votes (and those abstaining) were Democrats. Third, who is passing all the laws requiring women to be vaginally probed before they can get an abortion? Who wants to force their religious values on others? Etc... The Republicans want just as big of a police state as the Democrats, they only have a couple of minor differences on what to enforce. The NSA has been with us for a long time, through multiple power shifts and no one has reigned it in.
In summary. The US does not have a party that is "left of center." Democrats suck. Republicans suck more.