What the first debate means for candidates' strategies tonight; Frontrunners to square off in second Dem debate tonight; Biden, Sanders, Harris & Buttigieg in debate tonight; Obama campaign strategist on make-or-break debate moments; Supreme court rules fed courts can't stop questionable political district mapping; Chief Justice Roberts sides with liberals on census case, conservatives on district mapping; Supreme court blocks citizenship question from 2020 census for now, returns case to lower court; Trump suggests delaying 2020 census over supreme court ruling; House about to vote on senate's $4.6B border bill; Pelosi: House will pass senate's $4.6B border bill; Pelosi: Dems will "reluctantly" pass senate's border bill; Castro: Border drowning deaths "should piss us all off"; TV gremlins haunt debate, but '76 SNAFU was worse via Knit