A group of conservatives and libertarians in New Hampshire have come up with a plan they hope will block former Gov. Jeb Bush (R-FL) from becoming the Republican party’s nominee for President.

The idea is to hold their own presidential caucus in October and select a candidate behind whom they would all unite.

The group is called the “603 Alliance,” named after the only area code in New Hampshire. According to a report by Politico, the plan was instigated by “years of simmering discontent within the state Republican party,” as conservative, libertarian, and Tea Party activists have grown increasingly frustrated with the moderate Republicans who have won the state’s primary in recent years.

The condensed Republican primary schedule and reduced number of debates planned for this election cycle only heightened their motivation to organize and give their support to a single conservative candidate to defeat Bush.

The frustration goes beyond just moderate presidential candidates like Sen. John McCain (R-AZ) and former Gov. Mitt Romney (R-MA), extending to intraparty fights for control of the state Republican party and ideological battles during primaries.

Two of the 603 Alliance organizers, Tea Party activist Jack Kimball and libertarian Andrew Hemingway, have been on the front lines of these battles. Kimball was briefly the party’s state chairman in 2011 until being ousted by establishment Republicans led by New Hampshire’s top Republican elected officials. Hemingway was defeated in the gubernatorial primary to Walt Havenstein, an establishment candidate who lost the general election last year.

The establishment’s support for former Sen. Scott Brown, who had represented Massachusetts in the Senate for one term before moving to New Hampshire for a second attempt, over more conservative candidates with longer ties to New Hampshire, further grated the nerves of conservatives.

The plans for the 603 Alliance were partially formalized last week, when organizers gathered together about two dozen supportive groups in Concord, where they discussed how to form their coalition, the minimum threshold of conservative credentials they expected in a candidate, made plans to invite candidates who passed muster to come meet with the coalition, and started organizing a caucus-like process that they intend to hold in October of this year.

The group already hosted an event with Ted Cruz last Friday, and according to organizers, about thirty groups have expressed interest in participating in the coalition.

As Breitbart News reported, Bush has a slight lead in the latest New Hampshire poll, winning 19 percent, followed by Gov. Scott Walker (R-WI) at 14 percent. However, 24 percent of poll respondents were undecided, and seven other candidates–Sen. Rand Paul (R-KY), businessman Donald Trump, Sen. Ted Cruz (R-TX), Gov. Chris Christie (R-NJ), Sen. Marco Rubio (R-FL), former Gov. Mike Huckabee (R-AR), and retired neurosurgeon Ben Carson–were splitting 32 percent between them. The end result is that multiple candidates have the potential to overtake Bush, especially this far in advance of the primary.

New Hampshire Republicans do tend to be more moderate than Republicans in other states, especially on social issues. The same poll cited above showed that 49 percent identified as pro-choice on abortion and 43 percent support legalizing same-sex marriage, for example.

Another challenge besides the state’s more moderate Republicans is that, historically, three out of every ten voters in the New Hampshire Republican primary have been independents. New Hampshire law allows them to vote in either party’s primary.

Members of the Republican establishment are scoffing at the 603 Alliance’s plans. David Hess, a moderate Republican who has served as a State Representative for 25 years, told Politico that he was sure the group’s efforts were “destined to failure.”

Still, supporters of the 603 Alliance are determined. “We need to do something to give conservatives more of a voice at all levels of government,” said Jim Kofalt, a member of the 603 Alliance’s steering committee.

Kofalt acknowledged the challenges of getting people to commit to support their second or third choice candidate. “That’s always a struggle, but the reality is people can get behind their second choice candidate or they can end up with conservatives being fragmented and ultimately locked out of the process.”

“If you can sway even 10 percent of the primary vote, you’ve got a very good chance of getting a better candidate,” added Mike Rogers, another member of the steering committee.

The 603 Alliance will announce the full details of their plans at a summit scheduled for April 19 at the Crowne Plaza Hotel in Nashua. The New Hampshire Presidential Primary will be held on February 9, 2016.

Follow Sarah Rumpf on Twitter @rumpfshaker.