There has been enthusiasm for the notion of independence at the far fringes of Texan politics for decades, but the re-election of Barack Obama has significantly broadened the TNM's base.
The organisation claims more than a quarter of a million members, and has registered more than three million hits on its website since November.
It even formed its own Political Action Committee, or PAC, to back candidates who share its goals.
Last month, the Obama Administration rejected a petition calling for the state's secession from the US. Posted on the White House website in November by a student from Arlington, the petition drew 125,746 signatures in just eight weeks. Similar appeals emerged from all 50 states, but the Texan's was by far the most-signed.
In his response, the director of the White House Office of Public Engagement, Jon Carson, claimed the US Constitution, "enshrined ... the right to change our national government through the power of the ballot - a right that generations of Americans have fought to secure for all. But they did not provide a right to walk away from it."
The petition was rejected, but this week Texas got its first taste of international diplomacy - and its first ally - in the shape of the former Soviet state of Belarus, ruled by brutal dictator Alexander Lukashenko.
Apparently fed up with constantly being criticised for abusing human rights, the Belarus Ministry of Foreign Affairs levelled the same accusation at Washington for rejecting Texas's call. Whether Minsk's intervention will help the secessionist cause is open to debate.
Texas was briefly a nation, between securing independence from Mexico in 1836 and annexation by the United States in 1845, during which time it had embassies in London and Paris.
Alone, the state would boast the world's 15th-largest economy.
At a Tea Party rally in 2009, Governor Rick Perry gave hope to secessionists by suggesting, "When we came into the nation in 1845 ... we were a stand-alone nation. And one of the deals was, we can leave any time we want.
"So we're kind of thinking about that again." (Last year, Perry's office informed the Dallas Morning News that the Governor, "believes in the greatness of our Union".)
One person who could reasonably expect support from the movement's PAC is Larry Kilgore, a 48-year-old telecommunications consultant, who changed his middle name to "SECEDE" in December. Kilgore received 250,000 votes when he contested the Republican Senate primary in 2008, and has announced his intention to run for Perry's job in 2014.
His aim, he said, is to become Governor and then immediately hold a referendum on independence, before stepping down. "I don't want people to think I'm just interested in power," he explained.
Kilgore's reasons for advocating secession are partly economic. He resents paying social security and federal income tax.
Also, "We're not even allowed to execute people who molest children," he said. "We don't want the US coming in and saying, 'You can't perform this judicial punishment'."
- Independent
