white house planners say they 're ready to recommend spikes at the top of the mansion 's fenceposts to better protect the president .
move comes after several fence-jumpers , including one who sprinted inside the white house .
tennessee democratic rep. steve cohen asked the acting secret service director in november if 1600 pennsylvania avenue needed a six-foot moat .
that idea was actually under consideration , but later scrapped over maintenance concerns and ` having to retrieve people from it '