When Texas Republicans assemble for their state convention next month, it's possible they will debate whether the state should secede from the United States.

There's almost no chance Texas Republicans will actually vote in favor of seceding, mind you — not least because most of the party wants nothing to do with this — but the fact we're even mentioning secession and the Texas GOP convention in the same sentence suggests that the once-fringe movement has become a priority for at least some conservative grassroots Texans.

To be sure, that seems to be a relatively small group. The Texas secession movement says 22 out of the 270 county GOP conventions passed some kind of independence resolution this spring. A party official said he'd be "surprised" if that were the case, and the Houston Chronicle was able to confirm only 10 counties. But 10 is a lot more than the one county that passed an independence resolution in 2012.

Texas Republicans say these independence resolutions are just a handful of tens of thousands various resolutions to be considered at their convention. But it does seem like the secession movement is growing, or at least organizing, and may have become too big for party officials to ignore.

The Texas Tribune thanks its sponsors. Become one.

"It's cropped up in a major way just in this last year," Paul Simpson, chairman of the Republican Party of Harris County, told the Houston Chronicle.

Here's a rundown of what you should know about it:

First, some history

Let's boil down Texas history in two paragraphs:

In 1836, a scrappy Texas won its independence from Mexico in a bloody war (Remember the Alamo?). The newly minted Republic of Texas experimented with running itself as its own country before going broke and voting to join the United States.

In 1861, Texans voted to secede and join the Confederacy during the Civil War. When the war was over, the Supreme Court decided — in a case brought by none other than Texas — that states can't secede unilaterally and any attempt to do so will be "absolutely null."

The Texas Tribune thanks its sponsors. Become one.

Here's what modern-day secessionism looks like

As Texas's earlier history makes clear, a variant of the Texas secession movement has refused to die. It has ebbed and flowed in Texas for the 150 years since. The modern secession movement revved up again in the 1990s under a controversial leader, Richard Lance McLaren, who took a more violent tack to get his point across — including kidnapping. He is currently serving a 99-year prison sentence related to that incident.

The Texas Nationalist Movement took over from there and has advocated a more political approach. They've attempted to get language advocating for secession on GOP primary ballots, and every four years, they've tried to prod a skeptical and reluctant Texas Republican Party into debating secession at its state convention.

So far, things seem to be going according to plan

At a 2009 rally, then-Texas Gov. Rick Perry hinted at secession (albeit tongue in cheek; he later made clear he doesn't support the idea). A subsequent 2009 Rasmussen poll found 1 in 3 Texans think their state has the right to secede, but if it were put to a vote, 75 percent of voters would decide to say with the United States.

Tidbits here and there since Perry's remark hint at a growing movement. After the 2012 presidential elections, the Texas Nationalist Movement reported its membership had gone up 400 percent and Web traffic up 900 percent. Bumper stickers and signs advocating for secession began popping up in the state.

A 2012 WhiteHouse.gov petition to secede earned more than 125,000 signatures and a response from the White House. (The response: No.) Last year, the group held speaking tours to try to promote their cause and get a non-binding resolution on the GOP primary ballot.

Today, the movement says it has advocates in most Texas counties and 200,000 members statewide (although those numbers are hard to verify and are just a small percentage of the state's 26.9 million population).

The Texas Tribune thanks its sponsors. Become one.

Which brings us to 2016, when at least 10 Republican county conventions — there are 254 counties in Texas, but some have two conventions — passed some kind of item expressing support for Texas independence or at least debating it.

Despite Perry's joke, most Texas Republican leaders want nothing to do with this

The reasons are fairly obvious, but we'll spell them out anyway: Texas Republicans think the secession movement is unrealistic, unconstitutional and it opens them up to Democratic attacks that they're wasting their time on extreme ideas instead of actually governing the state. (Republicans dominate the state: In the 2014 general election, Republicans swept all 15 statewide races on the ballot and maintained their 16-year winning streak. They also have firm control of both houses of the Texas legislature and all of the state's governing boards.)

Texas Republican leaders would much rather ignore this pesky secession movement. But in recent years they've been forced to deal with it.

This fall, the group tried to get 75,000 signatures to get a secession-related resolution on March's GOP primary ballot. It read: "If the federal government continues to disregard the constitution and the sovereignty of the State of Texas, the State of Texas should reassert its status as an independent nation."

In December, the state party took matters into its own hands and voted down the idea. The movement doesn't even have "Republican" in its name, one state party official said. Another said he was "sorry we are even having the conversation."

In return, the secessionists immediately laid the blame at the party's feet: They "are of the same mindset as the bureaucrats in Washington," the group said.

Texas Gov. Greg Abbott probably didn't help quell the movement when he called for a convention of states this January. This is an idea that pops up among Republicans from time to time — Marco Rubio's a fan — to help states regain some of the control from the federal government.