"Mr. Trump is obviously no fan of immigration (while) Secretary Clinton is just the opposite, she's all in on immigration," he told CNBC's "Squawk Box" on Friday.
Clinton's perspective would be positive for the economy as more immigration would be "a big plus," Zandi said.
Trump, in what was billed as a key policy speech in Arizona on Wednesday, doubled down on a harsh anti-immigration stance, vowing to deport "millions" in his first hour in office and insisting he could force Mexico to pay for a wall along the two countries' nearly 2,000-mile-long (3,200 km) border. Mexican officials have repeatedly said the country won't be paying for the wall.
In contrast, Zandi noted Clinton's support for the Border Security, Economic Opportunity, and Immigration Modernization Act of 2013, which passed the Senate, but failed to clear the House of Representatives.
A report from Australian bank ANZ last month said that bill would increase family-based and skill-based immigration and increase the number of temporary immigration visas for skilled and unskilled workers, citing a Congressional Budget Office estimate that it would boost the number of immigrants by around a million a year over ten years.
"(Clinton's perspective on immigration means) more educated, skilled workers coming into the country, which is what the country desperately needs, given the slowing in the working age population. And it also empowers those undocumented workers, who now are very nervous and scared, (who) can't move around because they are illegal and undocumented, to find jobs that are more suited to their skill sets and that should improve their wages and tax revenues and productivity, which is very depressed," Zandi said.
In June, Moody's released an analysis that was highly critical of Trump's economic policies, writing at the time that if all of the real estate mogul's policies were adopted, the economy would suffer a "lengthy recession," with 3.5 million fewer jobs.