Nothing. The senate hates Cruz far too much
This is a good guess, but as much as they hate Cruz, they probably like their own pay checks even more and an entire party mobilising against their own President's agenda will not be rewarded by either primary or general voters.
At a guess, the future of the IRS will be put into question. I assume it would be gone in its current form. Perhaps cruz will accept a replacement with reduced staff and power. A flat tax would be implemented, possibly higher than Cruz would like. Estate tax abolished. Corporation tax and CGT slashed. The EPA, Edication and Commerce and Interior would follow suit and be similarly defunded and defanged. The interior's federal lands will be sold off or passed off to states. States will be forced to implement vouchers and public schools would be forced to charterise. EPA would lose the authority to regulate carbon, Mercury and other such nasties and be effectively completely neutered. A handful of social issues would be pushed through - gun laws, religious freedom, abortion bans etc. funding of that wall thing, bans on so-called sanctuary cities and reversal of Obama's executive orders on migration.
In foreign policy, it's all a bit more mysterious. Cruz is not a Paulite nor is he a classic neocon. He has flip-flopped on trade but I donby he'lol make a move against FTA building. Similarly on policy towards Fussia and China I don't think he'll change much from Obama's policy beyond using angrier rhetoric - it's very hard for politicians to change State Department or Pentagon minds, who usually think in scales way longer than electoral cycles. perhaps the military brass will be rewarded more hardware in Eastetn Europe, like all those expensive nuclear defence programs that Obama cancelled. Even the iRan Deal will be hard to walk back on. It all depends if the US's allies end up thinking Cruz is a smart wily guy or merely a creep that can be ignored.
