Former President Barack ObamaBarack Hussein ObamaHarris grapples with defund the police movement amid veep talk Five ways America would take a hard left under Joe Biden Valerie Jarrett: ‘Democracy depends upon having law enforcement’ MORE joked with the crowd Thursday during his first appearance back on the campaign trail since leaving the White House, brushing aside chants of “four more years.” “I will refer you to both the Constitution, as well as to Michelle ObamaMichelle LeVaughn Robinson ObamaThe Hill’s Morning Report – Treasury, Fed urge more spending, lending to ease COVID-19 wreckage Budowsky: Michelle Obama or Tammy Duckworth for VP Michelle Obama urges class of 2020 to couple protesting with mobilizing, voting MORE, to explain why that will not happen,” Obama said as he rallied in Newark for Phil Murphy, the Democratic nominee for governor of New Jersey. ADVERTISEMENTObama appeared Thursday afternoon in his first stump speech since leaving office in January in the hopes of boosting Murphy, his former ambassador to Germany. Murphy is running against Lt. Gov. Kim Guadagno (R) in November’s gubernatorial election to replace a term-limited Gov. Chris Christie (R). Polling regularly shows Murphy with a steady lead over Guadagno ahead of next month’s election.