Check if you have registered a custom post type thats' slug is 'politics' ('rewrite' => array('slug' => 'politics')). If you use a custom post type that has the same slug as one of your pages, it is likely that WordPress will show you the archive page of your cpt instead of the page in your menu. If you do not need the cpt's archive you can set 'has_archive' => false for this custom post type.
Flush your permalinks after modifying the rewrite rules.