Good Monday morning. Here are some of the stories making news in Washington and politics today.
• What started out as a Felix-and-Oscar odd couple — a no-drama intellectual and a gregarious, shoulder-squeezing pol — evolved into a surprisingly close friendship unlike any between a president and vice president in modern times. This is the story behind the relationship between Barack Obama and Joe Biden.
• Despite doubts about his candidacy, Mr. Biden begins the race with substantial support from three key constituencies in his native state of Pennsylvania: suburban moderates defecting from the Republican Party under President Trump, black voters who were underwhelmed by Hillary Clinton, and working-class white voters.
• Attorney General William P. Barr and congressional Democrats clashed on Sunday over his scheduled testimony before the House Judiciary Committee this week, with Mr. Barr threatening to skip the session and the panel’s chairman threatening to subpoena him.
• As House Democrats return to Washington after a two-week recess, they will find a Capitol consumed by the Mueller report. But rank-and-file Democrats are not being propelled by their constituents into impeaching the…