Apparently being neither clearly "in" nor "out" but merely a possible is called "being on the bubble," a term possibly arising from auto racing. Leitch writes a couple of things worth quoting:
The Republican Party, top to bottom, would do anything in its power to keep Trump out of the debate, while for Fox (along with CNN), Trump not only means eyeballs, he means outstanding television. Tossing Trump in on stage turns every debate into a fiasco, which is bad for the Republican Party but ratings manna for the cable networks. We have finally found where Fox News and conservative politics diverge: Donald Trump.
It is an awful way to narrow this field, this non-primary primary. But as any seasoned college basketball fan can tell you, watching teams desperately scramble to avoid their bubble bursting is incredibly entertaining. Strap in. It’s gonna be a wild month. It’s going to be madness.
