5 things to know for March 18: 2024 race, Freeze watch, Russia election, Social media, Volcano eruption

CNN’s 5 Things brings you the news you need to know every morning.

A California superbloom is springing to life and will soon blanket some of the state’s dry landscape in vivid displays of abundant wildflowers. The colorful blooms, however, are notoriously sensitive to weather conditions — so there could be a short window to bask in their beauty. Here’s what else you need to know to Get Up to Speed and On with Your Day. President Joe Biden and former President Donald Trump are making their appeals to voters ahead of another round of primaries on Tuesday. During a rally in Ohio on Saturday, Trump warned that if he were to lose the 2024 election, it would be a “bloodbath” for the US auto industry and the country. The remark came as Trump promised a “100% tariff” on cars made outside the US, arguing that domestic auto manufacturing would be protected only if he is elected. Meanwhile, Biden’s campaign said it brought in $53 million in February, a sign of accelerating donor interest. Fundraising has been a bright spot for Biden’s reelection effort, even as he battles low approval ratings and some polls showing him trailing Trump in key battleground states. Tuesday marks the official start of spring in the Northern Hemisphere after the warmest winter on record. However, more than half the US population this week will experience temperatures at or below freezing. The chilly weather will be a shock for many in the eastern half of the country that experienced warmer-than-average temperatures this past week. The cold system is expected to ultimately creep into the Midwest, progressing south and east with time, while New York is set to drop to 45 degrees Tuesday, forecasts show. Temperatures in the Southeast Tuesday morning will be 10 to 15 degrees below normal for this time of the year. Several major cities, including Atlanta, Charlotte, and Birmingham, Alabama, are all expected to see temperatures drop into the low 30s by Tuesday morning. Russian President Vladimir Putin is set to tighten his grip on the country he has ruled since the turn of the century as early results from a stage-managed election indicate a predictably large victory for the Kremlin leader. With over 99% of ballots counted, Putin amassed more than 87% of the vote, according to preliminary results reported earlier today by Russia’s Central Election Commission. In his Sunday evening address, Putin also made an unprecedented break with his tradition of not uttering Alexey Navalny’s name, discussing his death and confirming discussions over a potential prisoner swap involving the late opposition figure. Navalny’s allies had previously claimed he was “days away” from being exchanged before his death. The Supreme Court is set to debate whether the White House crosses the First Amendment line in trying to thwart social media disinformation. Biden administration officials have for years persuaded social media platforms such as Facebook and X to take down posts that include misinformation about vaccines, the Covid-19 pandemic and the 2020 election, among other things. But the Supreme Court must now decide whether those efforts go too far — when the government, in other words, veers into censorship on social media that violates the First Amendment. The case could prove pivotal to the 2024 election. Its outcome could determine whether the Department of Homeland Security can legally flag posts to social media companies that may be the work of foreign disinformation agents seeking to disrupt the race.