Seems like he did this to not discourage Tea Party Movement people from helping him win the senate.
Speaking for myself who was at Tea Parties at which Cruz spoke, I would have still wanted him as a senator.
I think for now that is his job, and he should concentrate on it and work for the grass roots of the USA as he promised.
He failed on that in Mississippi which was a shame.
Would you have wanted that if you knew he was STILL a Canadian citizen?