What are you expecting that Cruz will do, which you have no faith that Trump will do?
Be more faithful in sticking to conservative principles (Trump’s vacillations over time make Cruz look like Peter the Rock).
Govern in a Constitutional manner. (Trump continually makes comments indicating he believes the presidency has powers it does not.)
Make FEWER deals. I don’t want deals. For example, I want the government shut down if the dems won’t cave on the budget. But forget closing national parks - a president Cruz would shut down the agencies that would hurt the democrats the most.
No touchback amnesty.
Cruz has already outlined several federal agencies he would work to shut down.
etc, etc, etc.
This isn’t very hard. Trump will do what is best for Trump, conservatives be damned.