The math does not support your argument.
And your assumptions do? How much of that 18% would go to Maes and what would the turnout be? Voters will go to the polls if they have something to vote for. They need a choice, not an echo.
Hickenlooper is viewed Very Favorably by 35% of voters in the state and Very Unfavorably by 24%.
For Maes, Very Favorables are 12% and Very Unfavorables 20%
Fourteen percent (14%) have a Very Favorable opinion of Tancredo, but 32% view him Very Unfavorably.