The Republican Base likes Trump because a potential Republican Party leader with an actual backbone is such a novelty and breath of fresh air.
Especially when one looks at the current Repub “leadership” of Boner and McSurrender, who based on performance and behavior, should be (are?) paid by the Democrat Party for services rendered.
As far as an objective person can tell, the Repub Party works for Obama.
Also, the Republican Base has low opinion of the Republican Party because the Repub leadership hates them, possibly even more than the Democrats do.
And the Base is tired of being despised by its own Party leaders.