Some media is well known for their bias -- Fox News being pro-Republican, MSNBC being pro-Democrat. On the internet, however, it can be more difficult to measure biases, but one thing is certain: Reddit doesn't like Romney.

On Tuesday, the day after the last presidential debate, 19 out of 25 links on the first page of Reddit politics were against Mitt Romney and 1 was against Paul Ryan. None were anti-Obama.

Here are five examples of the topics on the first page of the Reddit Politics feed:

Why doesn't Reddit like Romney?

Simply, this is explained by how Reddit works. To get promoted to the first page, a link needs to receive the most upvotes. Thus, the popularity of a link is in the hands of active Redditors.

Similar to most social media platforms, most active participants are young people under 35 years old. Considering that only 18% of the millennial generation (born after 1980) identify as Republican, compared to 31% who identify as Democrat and 45% as independents, the limited success of Romney on Reddit is logical.

Romney's poor success on Reddit is not limited to this platform. On the social media front, Obama has dominated the reach of the Republican nominee. On Facebook, Obama has 31,285,462 fans versus 10,515,620 fans for Romney. On Twitter, 21,264,784 people are following Obama, while 1,561,834 followers are following Romney.

With so many more Obama followers on Twitter, it is easy to see why, like on Reddit, Romney's missteps like Big Bird or his "binder full of women" comment have become viral. Similarly, hashtags such has #cantafford4more promoted for $100,000 by the Romney campaign have become successfully co-opted by pro-Obama users.

Why Reddit doesn't like Romney has less to do with Romney's personality than with the fact that the younger generation, which is the most active on social media platforms, tend to be more liberal. That trend seems unlikely to change in the future.