It's not supposed to. What normally happens when you see that is the wine thatis fermenting has foamed up, and that foam has pushed into the airlock, filling it with wine.
You have to get your airlock clear. Keep in mind if the airlock is plugged, you could have pressure building up. So, first gently pull up the edge of the lid (or carefully remove the airlock/bung) and allow any pressure that may be built up to release. Then pull the airlock off and clean the wine out of it. Check to see if it is plugged (will air or water pass through the main stem?). If it's plugged, clean out the plug or get another airlock. At this time you might want to clean the lid up some as well. Then sanitize and install the (now) clean airlock in the lid (which is back on the wine).
I had this happen with an apple wine - I had too much liquid in my primary. I ended up taking the lid off on a daily basis and scoop the foam off the surface until the fermentation settled down.