Go to the Imgflip Home Page, Click the "Streams" drop down in the upper left hand corner and look through the streams until you find "Politics". You can then choose to join that stream and you will be able to post memes there.
Fair warning, the full on "Politics" a lot of more conservative leaning (like yours truly) users, and there is a lot of really hardcore debate and downright trolling. If you wish to post more left leaning content, do your self a favor and post it in the smaller more obscure "PoliticsTOO" stream. There is much less painful reality there, and what ever garbage you can come up with is more likely to get upvotes.
Hope that was helpful!
Also nice user name (; there are more of us than you think...