Trump is dominating the Republican primaries. But even most Republicans support other candidates.
And there are more Democrats than Republicans. There are also a great any independents (non-aligned).
So even if Trump can marshal nearly 50% of GOP votes in one caucus state (Nevada), that's only about one-fifth of the voters.
The Dems have so much "oppo" ("opposition research," or "dirt") on Trump that - unless Cruz or Rubio beats them to it - they can make him look like the loose cannon/ egomaniac/ know-nothing he is.
So I'm not too worried.
Yet. We have a proverb: "Nobody ever went broke underestimating the intelligence of the American people."