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PRESENTING YOUR INDIANA PRIMARY FIELD GUIDE
It’s all coming down to the Hoosier State.

Indiana Republicans haven’t seen their state’s primary matter so much in 40 years. That’s because it’s been that long since the GOP nominating process has gone on this long.

The last time the GOP presidential hopefuls rumbled into the Hoosier State was 1976, when former California Gov. Ronald Reagan was giving chase to President Gerald Ford.

Reagan pulled off a narrow victory and, along with wins in Texas, Georgia and Nebraska, reclaimed momentum after back-to-back losses in April.

Reagan acolyte Sen. Ted Cruz certainly hopes for a similar storyline this year against frontrunner Donald Trump. But Cruz has some big problems with his preferred narrative. He has 46 percent of the delegates he needs to win, mathematically eliminating him from an outright victory.

Trump, meanwhile, is 81 percent of the way home and can only be denied in a contested convention that he promises would be an even uglier brawl than the race so far.

Indiana polls say Cruz is facing the elimination round of his run. Trump leads by 11 points in the Real Clear Politics average of polls for the state. Trump and his growing number of admirers in the party establishment are looking for Indiana to seal Cruz’s fate.

But reason an Indiana loss would be an extinction event for Cruz’s candidacy is that the state stacks up so well for him on paper. Its voters are very conservative, socially and fiscally. He was once seen as the favorite. Now, Republicans appear to have tired of their intractable, ugly nominating process, and the momentum is for Trump, or at least for surcease.

If Cruz wins in Indiana, those conservatives who are backing his candidacy more out of a desire to block Trump than to pick Cruz will begin to fall away in larger numbers. Their focus will shift quickly from the Republican nominating process to the possibility of a third party; perhaps the Libertarians, perhaps something new.

Cruz could, and probably would, vow to fight on in a bid to soak up as many delegates as possible in the final month of the race. But that would just make him a Republican Bernie Sanders – a man out of the running but looking to increase his bid price from the party and its presumptive nominee.

But Cruz could substantially right his listing vessel today with a comeback win. And if you get to know the people and places of Indiana, you’ll see why. Come with us for a tour of the 19th state.

By the numbers…
--57 total delegates
--30 statewide, 27 by congressional district
--Winner-take-all at state and district levels
--Open primary
--635,589 total ballots cast in 2012
--Last polls close at 7 p.m. ET

WITH YOUR SECOND CUP OF COFFEE…
Every basketball fan knows Indiana is the Hoosier State. There’s even a movie about it. But what many don’t know, including Hoosier fans, is where the word originally came from. The Indiana Historical Society casts some light on the mystery: “One of the earliest known uses of the term is found in an 1827 letter that states, ‘There is a yankee trick for you – done up by a Hoosier.’ …In 1831, Gen. John Tipton received a proposal from a businessman offering to name his boat the ‘Indiana Hoosier’ if Tipton would give him business in the area…The word ‘Hoosier’ was widely used by the 1830s. Around this time, John Finley of Richmond wrote a poem called The Hoosier’s Nest, which was widely read. He wrote the word as ‘hoosher’ and did not explain its meaning, which leads historians to believe that Finley felt his readers would already know and understand the word.”

NORTHWEST: BUCKLE OF THE RUST BELT
The outcome of this region is not in doubt: Trump, Trump and more Trump. The question is how many voters turn out.

Gary has definitely seen better days. The History Channel series about life after the extinction of the human race was partly filmed here.

Think of this like a smaller version of Detroit, in Wayne County, Mich. Trump won there by 13 points and can be expected to do even better here. Despite the whole casino thing

Lake County, which is home to Gary, is the second-most populous county in the state but provided only 3 percent of the total vote in 2012’s Republican primary. If Trump is going to deliver an Indiana knockout tonight he will do so in part by beefing up that number with lots of crossover Democrats and independent votes in the state’s open primary.

Lake County
--Population: 490,228
--Median household income: $49,617
--Race: Caucasian, 71 percent; black, 25 percent
--Adults with bachelor’s degrees: 20 percent
--2012 election: Obama 65 percent
--Residents 65 or older: 15 percent
--After native son Michael Jackson died in 2009, his father, Joe, and the local mayor teamed up to raise money for a museum dedicated to the pop star. Despite raising funds, no development has taken place yet.

NORTHEAST: GIDDY UP VALUES VOTERS
The large Amish communities in the northeastern quarter of Indiana are not the only socially conservative folks there.

Even in 2012, when he had already dropped out of the race, Pennsylvania Sen. Rick Santorum still carded 20 percent of the vote or more in some of the counties in this portion of the state.

The population center of the region is Ft. Wayne in Allen County, which produced the third-largest number of GOP primary votes four years ago, behind only two metro Indianapolis counties.

If Cruz has a chance at an upset it will begin with massive support and massive turnout in this corner of the state.

Allen County
--Population: 368,450
--Median household income: $49,124
--Race: Caucasian, 81 percent; black, 12 percent
--Adults with bachelor’s degrees: 27 percent
--2012 election: Romney 57 percent
--Residents 65 or older: 13 percent
--What some say was first ever professional baseball game was played on May 4, 1871 in Fort Wayne. The Cleveland Forest Citys took on Fort Wayne’s Kekiongas, but the match was rained out at the top of the ninth inning with the home team up by two.

INDIANAPOLIS: START YOUR ENGINES
As we have seen with most major cities in these primaries, they are usually more Democratic than the states as a whole. But liberal-leaning or not, Marion County is the most populous in the state and will be the largest trove of votes. Four years ago, 12 percent of all votes came out of Marion.

That’s good news for Trump, who has thrived in Democratic strongholds, especially in open primaries.

But, unlike other cities where the suburbs mostly fall in collar counties, Marion is an urban/suburban split. There are plenty of higher income households that might deliver for Cruz or even some vestigial vote for Ohio Gov. John Kasich. That’s the same story in Hamilton County immediately to the north.

Expect nearly one in five votes to come from Marion and Hamilton combined.

Looking south to the conservative confines of Johnson County, things might be a bit different. This ought to be Trump’s best showing in the metro area.

Marion County
--Population: 934,243
--Median household income: $42,378
--Race: Caucasian, 66 percent; black, 28 percent
--Adults with bachelor’s degrees: 28 percent
--2012 election: Obama 60 percent
--Residents 65 or older: 11 percent
--The first event held at the Indianapolis Motor Speedway was a helium-filled balloon competition in 1909.

SOUTH: SWEET APPALACHIA
The only problem Trump has with the southern part of Indiana is that there isn’t more of it. As we saw in the neighboring region of Illinois, this is going to be a Trump blowout region.

Though geographically large, it’s mostly rural and home to just 20 percent or so of the state’s population. But what it lacks in volume it makes up for in intensity. Places like Jasper in Dubois County, ought to deliver big for Trump as will other counties between the Wabash and Ohio rivers.

Dubois County
--Population: 42,461
--Median household income: $54,186
--Race: Caucasian, 98 percent; black, 1 percent
--Adults with bachelor’s degrees: 18 percent
--2012 election: Romney 63 percent
--Residents 65 or older: 16 percent
--Jasper, located here, is considered the “Wood Capital of the World” with numerous furniture companies like Kimball International and Masterbrand Cabinets based here.

BELLWETHER
For today’s contest the bellwether to watch is Harrison County, just over the Ohio River from Louisville, Ky. Since 2000, this county has picked the GOP winner in every primary cycle within a fraction of the final statewide total.

Harrison County
--Population: 39,578
--Median household income: $53,483
--Race: Caucasian, 98 percent; black, 1 percent
--Adults with bachelor’s degrees: 16 percent
--2012 election: Romney 60 percent
--Residents 65 or older: 16 percent
--Home to vast underground caves where Daniel Boone and Squire Boone hid from Indians in the late 18th century. Squire Boone would later return and set up a homestead here.

[GOP delegate count: Trump 996; Cruz 565; Kasich 153 (1,237 needed to win)]

NO ONE CALLED ‘SHOTGUN’
True to his humble Indiana roots, native son President Benjamin Harrison wanted to be a fair leader to the nation’s newest states. After years of trying to establish statehood for the Dakota Territories, with much corruption and headache, Harrison didn’t want any further problems. Bismarck Tribune: “By 1884, Dakota had gone through a number of corrupt governors. This increased the demand for statehood. There was now a strong movement to have the territory divided with North Dakota and South Dakota coming into the union as separate states.  There also was an effort in southern Dakota Territory to get South Dakota admitted as a state and northern Dakota declared a territory…On Nov.2, President Benjamin Harrison signed the proclamation making North Dakota and South Dakota as the two newest states.  Since Harrison blindly signed the documents, we have no idea which one he signed first.”

Chris Stirewalt is digital politics editor for Fox News. Sally Persons contributed to this report. Want FOX News First in your inbox every day? Sign up here.

Chris Stirewalt joined Fox News Channel (FNC) in July of 2010 and serves as digital politics editor based in Washington, D.C.  Additionally, he authors the daily "Fox News First" political news note and hosts "Power Play," a feature video series, on FoxNews.com. Stirewalt makes frequent appearances on the network, including "The Kelly File," "Special Report with Bret Baier," and "Fox News Sunday with Chris Wallace."  He also provides expert political analysis for Fox News coverage of state, congressional and presidential elections.