Previewing what will be the biggest speech of Tim Walz' career

Minnesota Gov. Tim Walz will continue his introduction to the nation as he accepts Democrats’ nomination to be Kamala Harris’ running mate on night 3 of the DNC. Walz is a veteran, but Republicans have contested his service record.  Follow NBC10 Boston: https://instagram.com/nbc10boston https://tiktok.com/@nbc10boston https://facebook.com/NBC10Boston https://twitter.com/NBC10Boston