it's possible, but it's not really viable for anything. You can pull the mob with your main and pull it back, but there are problems with that, such as casters, runners, etc.

In PvP, enemies are always moving around so that would get really hard, trying to chase someone down with no long range. Also, CC like fear would screw you up.

In PvE, I suppose you could get away with it, but you're not going to have healing unless you have the druid SS out of Cat/Bear and heal, then go back.

As you can see, not the best thing to do - thats why most people pick shamans, or at least SOME long range.

On the other hand, you can have a paladin as your main and a long range as an alt. This lets you tank the mob in most cases, keeping that synergy.