Line type objects may be "partially" erased. Select the tool that you used
to draw or create the line, all of the nodes will appear. Place the cursor
over a node that you want to remove, and left click. The node will change
color. Hit the delete key and that node will be removed from the line. It's
one node at a time, but, you can gradually erase part of a line. You don't
have to start at an end point, by the way.