Polls open in less than an hour in Chicago, where Mayor Lori Lightfoot faces eight rivals — and a very real chance of being shut out of the likely April 4 runoff election. A new poll from Victory Research finds the incumbent trailing both former Chicago Public Schools CEO Paul Vallas and Cook County commissioner Brandon Johnson. Plus in just a few hours, President Joe Biden's student debt relief plan will come under the scrutiny of the Supreme Court, whose justices will decide in the months following today’s oral arguments whether the $400 billion program is constitutional. A lot more than debt relief for 40 million Americans is on the line. A broad ruling by the conservative high court might not only put a stake through Biden’s signature promise to young voters; it could cripple his plans to take executive action in other areas and leave federal policymaking more vulnerable to hostile states’ legal challenges. And the House Select Committee on China holds its first hearing this evening against a backdrop of rising trans-Pacific tensions, heightened by last month’s spy balloon revelations and recent speculation that China might overtly assist Russia with its invasion of Ukraine. The committee, operating so far with bipartisan cooperation, is supposed to take a look at the range of economic, technological and military concerns posed by China over the next two years. Subscribe to the POLITICO Playbook newsletter Raghu Manavalan is the host and senior editor of POLITICO's Playbook Daily Briefing.Jenny Ament is the executive producer of POLITICO Audio.