Markdown support is included with several plugins, however most of them implement it in an highly impractical way. Some of the plugins force you to save all the posts in markdown, while others need to convert to and from HTML on the fly, using additional server resources. Additionally, these plugins are usually just compatible with the text-based editor (with the exception of WP Markdown Editor which replaces the default visual editor with its own, but seems to have problems with the raw text editor).
If you want to write in markdown, you will be unable to use the special shortcuts the visual editor toolbar offers, for instance the 'Read more' button and the internal linking feature. Instead you will have to type these things manually, requiring you to open the post you want to link to in another tab to grab the link.
The ideal solution to this problem would be the ability to choose markdown as the format style for your posts, with it own specialized visual editor, possibly with a toolbar like the normal visual editor. A live preview (as in making the headings bigger and bold text bolder, like in the normal visual editor) to help with the writing would also be a great addition.
With this visual markdown editor it would be possible to choose between a visual editor with the regular functionality and a barebones text editor, while still writing markdown for your posts.
