Though it's 21 months until the Iowa caucuses and six months to the 2014 mid-term elections, the 2016 Republican presidential race is well underway, featuring an ideological cross-section of hopefuls including two Texans.
There's no way now to know how the contest will turn out. But it's not too soon to list some underlying factors that recur every four years because, based on past results, history often does repeat itself.
Here are some:
• Early coverage has focused largely on the efforts by Sens. Ted Cruz of Texas and Rand Paul of Kentucky to gain traction among the religious conservatives who comprise the largest portion of Iowa caucus voters. But at least one-third of past electorates have backed more moderate candidates and their favorite -- be it former Florida Gov. Jeb Bush, New Jersey Gov. Chris Christie or someone else -- will be a big factor, especially if a large group of hopefuls splits the conservative vote.
• Notice to Cruz: It's been 50 years since the most outspokenly conservative candidate won the GOP nomination. And Arizona Sen. Barry Goldwater (1964) got less than 40 percent in the general election and carried just six states. Similarly, the last time Democrats nominated the most liberal candidate was in 1972, when South Dakota Sen. George McGovern carried but one state.
• Winning in Iowa gets early publicity but not necessarily the nomination. Since the first contested Republican caucuses in 1980, only two of the six winners -- Kansas Sen. Bob Dole (1996) and Texas Gov. George W. Bush (2000) -- went on to win the GOP nomination. And losing badly can wreck your chances; just ask such well-known also-rans as former Sens. John Glenn of Ohio (1984) and Phil Gramm of Texas (1996).
• On the other hand, winning in New Hampshire is very important, as is winning in South Carolina. Five of the last seven New Hampshire winners won the GOP nomination, as did six of seven South Carolina winners, a streak not broken until 2012, when former House Speaker Newt Gingrich of neighboring Georgia defeated ultimate nominee Mitt Romney of Massachusetts. Geographical proximity helps. Counting both parties, four candidates from neighboring Massachusetts and one from Maine have won the New Hampshire primary. And Illinois Sen. Barack Obama in 2008 was the fifth from the region to win Iowa. Potential 2016 beneficiaries: Wisconsin Gov. Scott Walker and Rep. Paul Ryan, or South Dakota Republican Sen. John Thune.
• By early or mid-March, the race will be down to two or three candidates, presumably at least one representing the party establishment and one the conservatives. If Bush doesn't run and Christie craters, someone else will claim the establishment mantle. Meanwhile, Iowa, New Hampshire and South Carolina will weed out the conservatives.
• Running a prior presidential race is helpful, but not necessary. Bush in 2000 was the first first-time candidate since Goldwater to win the GOP nomination when the party was out of power. The two who might benefit from prior experience are Texas Gov. Rick Perry and former Pennsylvania Sen. Rick Santorum. But Perry still has to overcome the impact of his 2012 goofs, notably his inability to remember which Cabinet departments he proposed to scrap.
• Money counts. Failure to create extensive fundraising networks has crippled lesser known candidates who scored early successes, like former Arkansas Gov. Mike Huckabee (Iowa 2008) and two New Hampshire Democratic winners, Colorado Sen. Gary Hart (1984) and Massachusetts Sen. Paul Tsongas (1992).
These seven points may help to assess the chances of some candidates, but they won't predict the likely winner. Presidential campaigns are full of unexpected turns; just ask "Presidents" Phil Gramm (1996), Al Gore (2000) and (so far) Hillary Clinton (2008).
(Carl Leubsdorf is the former Washington bureau chief of The Dallas Morning News.)