NEWS FLASH: There are only 29 shopping days left before the Iowa caucuses!

The final four weeks between Monday and Jan. 3 will be a political junkie’s dream as a somewhat sleepy Republican presidential contest bursts into full view.

With candidates hopscotching between early-voting states, new television ads appearing almost daily, and attacks coming hot and heavy, it’s hard to know what will really matter between now and when Iowans cast the first ballots of the Republican race.

In an attempt to provide some clarity, below is the Fix’s CliffsNotes guide to what’s ahead before Iowa — our attempt to see the forest through the trees. In short, these are the most important moments.

The Des Moines Register endorsement: Regular readers know that we are skeptical of the power of endorsements, but with six in 10 likely Iowa GOP caucusgoers in a new Des Moines Register poll saying they are open to changing their mind about a candidate, the support of the state’s largest and most influential newspaper is not to be scoffed at. While the Register endorsement probably has less sway in a Republican primary than in a Democratic one, it still matters — and any of the candidates would love to have it.

The two most likely endorsees are former House speaker Newt Gingrich (Ga.) and former Massachusetts governor Mitt Romney. They haven’t spent the most time in the state — former senator Rick Santorum (Pa.) and Rep. Michele Bachmann (Minn.) have that distinction — but they stand at the top of most Iowa surveys.

A Gingrich endorsement would solidify his Iowa front-runner status. If Romney is the Register’s pick, it might give him the necessary momentum to win over the large faction of voters who are still on the fence. A look back at 2008, however, is a reminder not to make too much of the Register endorsements. In that election, the paper picked Sens. Hillary Rodham Clinton (she finished third) and John McCain (fourth).

The Iowa debates: The narrative of the Republican race has been defined by the (many) debates. So it’s no surprise that the last two before the Iowa caucuses will be important, particularly considering that both will be in the Hawkeye State.

On Saturday, the candidates will gather at Drake University in Des Moines (Go, Bulldogs!). Five days later, they’ll square off in western Iowa — Sioux City, to be exact. Those two debates will be the last, best chance for Iowa Republicans to get an extended view of Gingrich and Romney. The forums are of particular import for Romney, who has recently started spending money on television in the state, a sign that he thinks he can win.

The final Register poll: The survey, conducted by J. Ann Selzer, has an uncanny record of getting the Iowa finish right. The last Register survey before the 2008 caucuses came out on the final day of 2007. It showed Sen. Barack Obama (Ill.) leading the Democratic race with 32 percent and former Arkansas governor Mike Huckabee on top of the Republican field with 32 percent. Obama won with 38 percent, and Huckabee won with 34 percent. Not too shabby.

Aside from its predictive abilities, the Register poll could influence Iowa Republicans who haven’t made up their minds by that point. Human nature dictates that we like to be with a front-runner — New York Yankees fans, I am looking at you — and Gingrich, Romney or, gasp, Rep. Ron Paul (Tex.) could benefit from a landslide of late deciders if one looks like the winner.

Steve King endorsement: The conservative congressman represents broad swaths of western Iowa, the geographic center of the Republican Party in the state.

In 2008, King, somewhat oddly, backed former senator Fred Thompson (Tenn.), who went on to finish a distant third in the caucuses. This time, the congressman has taken a more measured approach but has made it clear that he plans to make an endorsement. (King has been careful not to tip his hand, although he did tell Radio Iowa’s O. Kay Henderson that Gingrich’s relatively moderate position on illegal immigration “makes it harder” for him to support the former House speaker.)

With other Iowa Republican political powerhouses such as Sen. Chuck Grassley and Gov. Terry Branstad unlikely to wade into the Republican race before Jan. 3, the King endorsement may be the most coveted one left for the GOP contenders.