One of my personal favorite classes has always been Western Pleasure so I'm delighted when I'm asked for help with this event. Since we do mostly Arabians, I was helping someone with a half-Arabian recently and the discussion got around to length-of-rein.
People seem to be overly concerned with length of rein. There are currently two thoughts on the matter: drape vs light contact. I believe that framing the discussion around rein length is misleading, what makes a good Western Pleasure horse is self carriage. Self carriage is taught through collection, riding the horse up into the bridle. When a horse can truly carry his frame, the cues can become very subtle. The horse does not touch the bridle nor does the rider, which allows the frame to remain unchanged during transitions. The horse can then go around the ring in an easy, consistent and effortless manner.
The reins are a line of communication. A shorter rein means a shorter communication. That's why Trail horses and Reining horses are usually on a shorter rein. The classes are much quicker with shorter amounts of time and distance to make transitions that are also more difficult than Western Pleasure. But a longer rein that's appropriate for Western Pleasure allows a horse to listen attentively to other cues (all well trained horses learn to do this) but it's about degree or amount in Western Pleasure. That's why Joanne Salisbury's horse VP Midnitestranger +// ("Wes") carried a longer rein in Western Pleasure than in Trail and Western Riding. Incidentally, he also carried a different bit in Western Pleasure.
The longer rein in Western Pleasure means the horse needs little help from his rider and that is what makes Western Pleasure so special.
I don't think the quetsion is soft contact vs long rein but rather how much drape a horse can handle and still carry himself well. And remember that confirmation is a very big factor in this as well as a horse's overall confidence in himself. Western Pleasure horses should not be "hand ridden" but should carry themselves in an easy manner, exhibiting beauty and quality of movement. The best horse in the ring is not necessarily the horse with the longest rein, but the one going along in a collected and soft manner with little help from his rider. See you next week! JD