There's a lot of loose talk in Republican politics about the battle that's supposedly raging between outsiders and the mainstream establishment. Actually, the battle's over. It's the outsiders in a romp.

Look at the poll numbers, as averaged by Real Clear Politics. They show the relentlessly growing combined strength of the four main outsider presidential primary candidates: Donald Trump, Ted Cruz, Ben Carson and Carly Fiorina. Only Cruz, a Texas senator who routinely defies his party, has held elective office. Trump and Fiorina are business leaders and Carson is a retired neurosurgeon.

This month's polls show 64 percent of likely Republican primary voters favoring one of those four. Just 23 percent support one of the best-known insiders: former Governor Jeb Bush of Florida, Senator Marco Rubio of Florida, Governor Chris Christie of New Jersey or Governor John Kasich of Ohio.

That represents a huge shift. Back in June, when Trump was just getting into the race and Cruz was little known, the four insiders were way ahead of the four outsiders, 35 percent to 23 percent.

It took until August for the tide to turn toward the anti- establishment group, with the outsiders taking a 33-percent- to-26-percent lead. A month later, support for the outsider quartet had risen to 51 percent, versus 24 percent for the insiders.

To comfort themselves, establishment Republicans like to recall the fall that followed the fleeting rise of past outsider presidential primary candidates like Pat Robertson in 1988, Steve Forbes in 2000 and Herman Cain in 2012. Top Republican office-holders, strategists and lobbyists keep saying that Cruz and Trump will suffer the same fate.

The poll numbers suggest that may be delusional. It seems clear now that grass-roots Republican voters have a deeper, and probably more durable anti-establishment feeling than in other recent elections. Things have changed since the days of Herman Cain.

Now, when one of the anti-establishment candidates slips, most of his or her support goes to another outsider. When Carson dropped recently, for example, Cruz gained.

This is reinforced by a Pew Research September survey in which 65 percent of Republicans said they wanted a candidate with "new ideas" as opposed to one with experience. That was a sharp reversal from six months earlier, when most Republicans preferred experience.

Democrats go the other way, valuing experience over new ideas by 53 percent to 39 percent.

Why the shift among Republicans? One factor may be the personal appeal of these four outside candidates. Trump, of course, was a reality-TV star.

It also probably reflects the undelivered promises many Republican candidates have made in recent elections to slash government programs and defeat a Democratic president they detest. Realism aside, the sense of betrayal among many rank- and-file Republicans is likely to be inflamed further by Republican congressional votes Friday that passed a year-end spending bill and averted a threatened government shutdown.

The liberal Washington Post columnist Dana Milbank wrote last week that if only Bush, Rubio, Christie and Kasich would unite behind one candidate, he could probably beat Trump or Cruz. This increasingly looks dubious.