This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A central region, especially one that is politically, economically, or militarily vital to a nation, region, or culture.

n. The centre, or most populous part of a region defined by geographical or non-geographical criteria.

n. the central region of a country or continent; especially a region that is important to a country or to a culture

"I think aides were saying that this issue is clearly important to everyone in this country, and so therefore they felt like no better place for the president to announce it than from what they call the heartland here in Crawford, Texas."

region   

exceptionalism    segregationists    slipped0.33    powerhouse    proletariat