Ted Cruz has “nothing against Canada.”  Likewise, many Canadians born in US have”Nothing against United States (until now).
Here is an article by Lynne Swanson (aka Blaze) which appeared on the Congress blog at The Hill today.
This tells Senator Ted Cruz he has nothing to fear from Canada for renouncing Canadian citizenship–unlike what happens in reverse

Senator Cruz, Canada respects your decision to renounce your Canadian citizenship. When it is granted, I assure you Canada will not stalk you for information about your private finances and will not demand taxes or penalties from you.
Senator Cruz, will you and your Congressional colleagues do the same to protect Canadians and others around the world from outrageous demands of IRS and US Treasury?