>>4899298
tl;dr eminent domain is the right for a government, local authority etc to claim land owned privately for an ostensibly public purpose in return for compensation.
Why it's an issue in this election is because Cruz and Jabe! tried stumping the Trump by claiming that - as a hotel developer - he's in favour of it being abused for private gain.
Leading to a hilarious claim by Jabe! that the Keystone pipeline is for a purely public purpose
>>4899583
The difference is that Cruz tried stumping Trump with Trump's support for eminent domain