American progressives tend to use Sweden (and Scandanavia generally) as models of how socialism can succeed, probably unaware that Sweden is a highly-productive, modern, capitalist society with capiitalist notions free trade, property rights, investment freedom, and monetary policy. In other words, socialists love to provide examples of socialism that are pretty devoid of actual socialism. Sweden has high taxes and a generous welfare regime, but it doesn't have government ownership of the means of production ("socialism"). That's why Sweden is Sweden.
And Sweden's economic growth rate stagnated after it adopted large social welfare programs in the 1970s, and only somewhat recovered when it instituted market reforms in the late 90s and 2000s, including reductions in social benefits and income tax cuts.
Source: Heritage foundation's economic freedom index (Sweden does very well: http://www.heritage.org/index/country/sweden)