"Solid South" meaning in English

{
  "forms": [
    {
      "form": "the Solid South",
      "tags": [
        "canonical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "def": "1",
        "head": "Solid South"
      },
      "expansion": "the Solid South",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "US politics",
          "orig": "en:US politics",
          "parents": [
            "Politics",
            "United States",
            "Society",
            "North America",
            "All topics",
            "America",
            "Fundamental",
            "Earth",
            "Nature"
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          "source": "w"
        }
      ],
      "glosses": [
        "The electoral support of the Southern United States for Democratic Party candidates for nearly a century from 1877, the end of the Reconstruction, to 1964."
      ],
      "id": "en-Solid_South-en-name-cdWVAiT~",
      "raw_glosses": [
        "(US politics, historical) The electoral support of the Southern United States for Democratic Party candidates for nearly a century from 1877, the end of the Reconstruction, to 1964."
      ],
      "tags": [
        "US",
        "historical"
      ],
      "topics": [
        "government",
        "politics"
      ],
      "wikipedia": [
        "Solid South"
      ]
    }
  ],
  "word": "Solid South"
}

{
  "forms": [
    {
      "form": "the Solid South",
      "tags": [
        "canonical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "def": "1",
        "head": "Solid South"
      },
      "expansion": "the Solid South",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English proper nouns",
        "English terms with historical senses",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:US politics"
      ],
      "glosses": [
        "The electoral support of the Southern United States for Democratic Party candidates for nearly a century from 1877, the end of the Reconstruction, to 1964."
      ],
      "raw_glosses": [
        "(US politics, historical) The electoral support of the Southern United States for Democratic Party candidates for nearly a century from 1877, the end of the Reconstruction, to 1964."
      ],
      "tags": [
        "US",
        "historical"
      ],
      "topics": [
        "government",
        "politics"
      ],
      "wikipedia": [
        "Solid South"
      ]
    }
  ],
  "word": "Solid South"
}