Donald Trump Jr. will endorse Arizona Senate Republican candidate Kari Lake on Thursday for U.S. Senate, the Daily Caller has first learned. Trump Jr. said Lake would be the perfect candidate to stand up to the Democratic Party and help pass his father’s agenda in Washington, should the former president win in November. He also said she will deliver on border security and economic security for Arizonans. “Kari Lake is a proven America First leader and will be the next Senator from Arizona. I am proud to join my father in endorsing her campaign. Kari will always fight to secure the border, cut …