Convulsion in the Republican Party may not be quite what it seems. It isn't a war between the grass roots and the establishment, between the conservative and the moderate factions, or the new and the old.

It's not about ideology, tactics, or strategy, as Tea Party people and movement conservatives are on both sides of the struggle. It's about an attempt by Heritage Foundation President Jim DeMint and a small group of people to turn the Republican Party into the conservative movement, which is going to fail because it's simply not possible.

It’s going to fail for one simple and obvious reason: Movements and parties complement each other, but have dissimilar functions. Movements and parties fill different purposes.

Movements and parties are different things. Movements are close, tightly-formed collections of like-minded thinkers; parties are loose groups of all the left-center or center-right factions, from those close to the center to those near the fringe.

Movements aim to extend their control inside their own parties; parties try to mass coalitions wide enough to win power. Movements give parties their form and coherence, parties give movements their access to power, as none are large enough to prevail on the the national stage on their own.

Movements always chafe at the restraints put upon them by the parties’ urge towards consensus, but until they break the 50-percent mark in national polling, they must depend on soft party members and moderate squishes to give them the victory edge.

Now and then, a pure movement figure — a Barry Goldwater or a George McGovern — breaks through to be nominated, but the institutional party always deserts them, donors close checkbooks and moderates flee.

When a movement tries to take over a party, it ends badly for both of them. But the intent to do so, it seems, never dies.

“My 80-percent friend is not my 20-percent enemy,” said Ronald Reagan, who built a huge coalition of moderates, independents and conservative Democrats around his movement's conservative base.

To DeMint and his friends at Heritage Action, their 98-percent friend is their two-percent enemy, as they rail, curse and hurl primary challenges at other conservatives who differ with them only on tactical matters or small unimportant details.

Nothing enraged Senate Republicans more than being assailed by Ted Cruz and Mike Lee as the ‘surrender caucus' (while nobody mentioned the Democrats) or having them try to manipulate House members to undermine leadership strategy.

Let’s not forget that DeMint once said he would have rather have 30 Republican senators who thought the way he did than 60 who didn’t, ignoring the fact that this would mean unrestrained liberal governance.

Let's not forget too that Obamacare was brought to you by the Senate Conservative Fund, whose threat in 2009 to run a primary opponent against Arlen Specter sent him running back to the Democrats, where he became one of that act's most fervent defenders as well as its critical 60th vote.

More and more, it seems that the drive to "defund" Obamacare was more a device aimed at smoking out “RINOs” than at stopping the act in its tracks.

“Outside conservative groups ... have raised real cash on this venture, and they've spent most of it attacking House and Senate Republicans,” writes the Wall Street Journal's Kimberley Strassel, while Democrats got off scot free.

Meanwhile, the squish list grew to include Sens. Tom Coburn of Oklahoma, Jeff Flake of Arizona, Jeff Sessions of Alabama and all of the star class of Tea Party governors, who to a man were opposed to the shutdown, and moreover, had gotten things done.

Not in the same class as wrecking the party, in the glorious name of saving the movement. But if the party dies, then the movement does, too.

Noemie Emery, a Washington Examiner columnist, is a contributing editor to The Weekly Standard and author of "Great Expectations: The Troubled Lives of Political Families."