Widespread flooding in southern California is turning hillsides into rivers of mud, as a slow-moving storm brings life threatening conditions to the Los Angles area. Both Democrats and Republicans will head to the polls in Nevada on Tuesday to vote for their party's presidential nominee, but many Republicans won't have all the choices on the ballot. And Dartmouth college is reinstating standardized testing requirements in admissions, citing research that shows it might help disadvantaged students.Want more comprehensive analysis of the most important news of the day, plus a little fun? Subscribe to the Up First newsletter. Today's episode of Up First was edited by Megan Pratz, Sadie Babits, Nichole Cohen and Mohamad ElBardicy.It was produced by Ziad Buchh, Ben Abrams and Julie Depenbrock.We get engineering support from Phil Edfors. And our technical director is Stacey Abbott.