Brandon Johnson took office Monday, facing an influx of migrants in desperate need of shelter, pressure to build support among skeptical business leaders, and summer months that historically bring a spike in violent crime.

Progressives viewed Johnson’s election as evidence that bold stances lead to victory at the ballot box. Now, his first term leading the nation’s third-largest city will test the former union organizer’s ability to turn those proposals into solutions for stubborn problems worsened by the coronavirus pandemic, including public safety, economic growth and housing affordability.