Last March, FiveThirtyEight—the statistically oriented media site founded by renowned pollster Nate Silver — noted that the prospective Republican presidential field displayed more parity than any since 1976. For the last four decades, the analysts say, the leading Republican has always polled at least 23% in the corresponding time period. Nearly a year later, this remains the case.  While the Democratic Party has a clear heir apparent in former Secretary of State Hillary Clinton, the Republican Primary appears to be anybody’s game. With a diverse range of competitive candidates, ranging from the moderate and establishment-approved Jeb Bush, to Tea Party favorite Ted Cruz, to libertarian Rand Paul, the coming months will represent not just a close horse race, but a decisive battle in the war for the heart of American conservatism.

Referring to a conversation with an unnamed political consultant, Washington Post writer Chris Cilliza breaks down the GOP race into a set of four “lanes”: establishment, Tea Party, social conservative, and libertarian. Any of these routes, save perhaps libertarianism, could potentially translate into early primary victories, and the momentum necessary to reach the Republican National Convention sixteen months from now in Cleveland. However, present conditions suggest that the Republican primary will boil down to a familiar clash between the GOP’s moderate center and its Tea Party affiliate.

Of the four niches mentioned, only the market on libertarianism has been solidly cornered by one candidate. However, Senator Paul’s characteristic non-interventionism is unlikely to benefit his already-outsider status, with public opinion supporting military action against the Islamic State and turning against President Obama’s decision to pull out from Iraq in 2011. Paul has lately shifted to more aggressive foreign policy positions, saying that as President he would “seek congressional authorization to destroy ISIS militarily,” but the about-face also could hurt his credibility, especially in light of “war hawk” allegations he leveled against Clinton last fall.

In 2012, social conservative and former Pennsylvania Senator Rick Santorum pushed the better-funded and more-endorsed Mitt Romney nearly to the wire, pulling off a sensational string of primary victories in the South and Midwest before finally succumbing in April. While Santorum has significantly improved his political infrastructure and blue-collar credentials since that election — having founded the Patriot Voices PAC and written a book which outlines his commitment to serving the needs of the working class — he may be hobbled by competition in 2016.

Former Arkansas Governor and 2008 candidate Mike Huckabee, who is gearing up for a presidential run and polling relatively strongly, also is characterized by his socially conservative platform. With the further addition of famed neurosurgeon Ben Carson to this pool, it becomes clear that no one candidate will stand out solely on the basis of his social views.  This is not to predict, of course, that Republican sensibilities about abortion and the family will prove irrelevant in 2016. However, unlike in 2008 and 2012, the more strongly religious elements of the part have not rallied behind one candidate—or at least show no signs of doing so just yet.

Candidates who hope to appeal to Tea Party voters do not uniformly occupy the party fringe. There do exist radical figures like Texas Senator Ted Cruz, hobbled in terms of general electability by his role in the government shutdown of 2013, but with the capability to drive the field to the right.  However, others — most notably Florida Senator Marco Rubio and Wisconsin Governor Scott Walker — have identified themselves with the Tea Party, while staying on good terms with the broader GOP. Rubio, for instance, was tapped to deliver the official Republican response to the State of the Union in 2013.

For this diplomacy between party sectors, both Rubio and Walker — Walker in particular — have stood early near the top of the field. The governor, however, has suffered under the media spotlight that has accompanied his ascendency. A recent pair of ambivalent comments — one over President Obama’s love for the country, and one over the theory of evolution — as well as a tacit comparison between his fight against union protestors and the war against the Islamic State, have kept the governor in the headlines, but in largely negative terms. Whether his candidacy will be able to sustain such a barrage of criticism, which has come from Republican rivals as well as the left, remains to be seen.

Finally, the field includes several moderate contenders. Preeminent among them, of course, is former Florida Governor Jeb Bush, who enjoys a broad base of donor support and good name recognition. Bush’s place as the candidate to beat was solidified in February when Romney ended serious speculation that he would run for the White House a third time.

Jeb Bush, like his older brother George Walker, has taken a much more sympathetic view of undocumented immigrants and immigration reform than many of his Republican peers. He has referred to their entry into the United States as an “act of love,” and in his book Immigration Wars, Bush advocated a comprehensive reform package similar to the bill passed by the Democrat-controlled Senate in 2014. He also supports Common Core standards for secondary education, and has gained a reputation as an innovative education reformer  during his tenure as governor.

Similar to Bush in many respects—a moderate governor from an important swing state — is Ohio’s John Kasich. A deficit warrior and generally orthodox conservative, Kasich has broke ranks somewhat on the issues of climate change and immigration, by acknowledging a problematic climactic trend affected by human activities and urging cooperation with the President on immigration reform. While his probable candidacy has not garnered much attention, Kasich has the potential to become a dark horse during primary season, and to attract Independent votes in a national election.

While the likes of Kasich, Bush, and New Jersey Governor Chris Christie (whose star has waned recently, but still remains in clear contention) constitute the party’s best chance both at winning votes needed to capture the White House and at governing productively if he gets there, each will face a hard primary battle to win over less centrist elements of the party. This was foreshadowed at last week’s Conservative Political Action Conference where activists organized a walk-out during Bush’s address. However, the moderates will be better served in the long run not by bending to pressure, swinging right, and compromising their electability as Romney did in 2012, but by continuing to move the party line on issues that require not just compromise but cooperation between parties. If they do, the eventual nominee and the party at large, should reap the rewards in November.