There are many blogs on the internet where you can find a variety of opinions about many topics. When it comes to anything that has to do with politics or any socially relevant subjects, many things could be said and many voices can be heard, that is the essence of Democracy.
In case you want to find an interesting blog where you can hear a liberal voice about politics, economics, health, and many other socially important topics Think Progress could be a good option for you.
This blog belongs to the Center for American Progress Action Fund, a politically unbiased organization that works in many fields with the purpose to contribute with social development. In case you decide to use this blog, you will be provided with a forum where you can contribute with and learn about progressive ideas and policies.
This is an awarded blog that was voted “Best Liberal Blog” in the 2006 Weblog Awards having an Official Honoree in the 2009 Webby awards. The blog is also known for receiving different awards for journalism excellence. In short, this is an interesting site in case you want to learn more about new perspectives. 
