During his time in DC, Tancredo gained a reputation as a bomb-thrower. He regularly issued strident attacks on his opponents (many of whom were in his own party), the primary purpose of which seemed to be to throw red meat to his ardent supporters. Based on his legislative record (what little of it there was) he had very little interest in actually accomplishing anything through legislation. His main interest was publicity.
As we all know, Tancredo's signature issue was illegal immigration. His approach to the subject was bombastic, and it was ineffective -- any chance he might have had in helping to craft immigration reform (if he even had an interest in doing so) was squandered by his practice of publicly excoriating anyone with whom he disagreed.
Based on his behavior, I got the impression that Tancredo, whatever his actual thoughts on the matter, viewed illegal immigration as a vehicle for self promotion; he certainly used it that way.
All of which sounds a lot like Trump.
And your description above is almost word for word the same Cruz's critics use to describe him.
To some he's self aggrandizing, to others he's speaking for a great many voters who have no voice in Washington. Which view you take usually aligns with whether or not you agree with the issues he advocates.
I may disagree with him concerning Trump but I never heard anything from Tancredo that led me to believe he didn't believe passionately in the issues he advocated.
