THERE IS NO MENTION WHATSOEVER OF A TARIFF IN THE TEXAS ORDINANCE OF SECESSION

So why does Alex Jones claim that the U S Civil War was about a tariff? 

Lots of mentions of white supremacy and preserving slavery.

But a tariff?

Pffft!

See :

DECLARATION OF CAUSES: February 2, 1861
A declaration of the causes which impel the State of Texas to secede from the Federal Union.