Vice President Kamala Harris’ running mate, Minnesota Gov. Tim Walz, took to the stage at the Democratic rally in Arizona on Friday night and cheers erupted as he took a shot at Donald Trump’s obsession with crowd size. His first line of the night was to remark on crowd size, addressing a packed crowd in the Diamond Desert Arena, a venue capable of holding nearly 20,000 people. “Hello, Arizona!” said Walz, to applause from the rally-goers. “Wow. Wow. You might have seen, a few people showed up in Philadelphia the other night. And then 10,000-plus walked into a field in western Wisconsin. And t…