washington group top u.s. house representatives democrats send letter tuesday ask department defense review pay appearance russian event retire army lieutenant general michael flynn president donald trump national security adviser letter say extremely concern flynn pay appear gala russia government-funded rt television anti-bribery emoluments clause u.s. constitution bar payments foreign governments remain unclear much general flynn pay dinner russian president vladimir putin whether receive additional payments russian foreign source separate occasion whether seek approval department defense congress accept payments say letter rank democrats six house committees ask letter white house spokesman sean spic say think department defense appropriate place review say appear unusual note flynn like think probably countless hundreds retire flag officer join speak bureau give speeches various place flynn former director defense intelligence agency warm relations putin government worry russia hawk congress consider moscow u.s. opponent issue range annexation crimea ukraine civil war syria hack last year u.s. election lawmakers also question flynn relationship government turkish president recep tayyip erdogan pay lobbyist consult firm lead head turkish-american business council last november election write article urge u.s. cultivate good relations erdogan democratic lawmakers want probe trump adviser 's russia payment