Voters in three key states head to the polls for primary runoff elections, the Supreme Court sides with President Trump over mail-in ballots and economic tensions continue to rise with Canada and Iran. For more context and news coverage of the most important stories of our day, click here: nbcnews.com » Subscribe to NBC News: nbcnews.to/SubscribeToNBC » Subscribe to Here's the Scoop podcast: nbcnews.com/heres-the-scoop-daily-podcast » NBC News App: apps.nbcnews.com/mobile » Breaking News Alerts: link.nbcnews.com/join/5cj/breaking-news-signup?cid=sm_npd_nn_yt_bn-clip_190621 » Visit NBCNews.Com: nbcnews.to/ReadNBC » Find NBC News on Facebook: nbcnews.to/LikeNBC » Follow NBC News on Twitter: nbcnews.to/FollowNBC » Follow NBC News on Instagram: nbcnews.to/InstaNBC #scotus #donaldtrump #canada