miami u.s. republican presidential front-runner donald trump come fire rival thursday say muslims hate unite state debate gut-punching attack early forums give way suddenly civil tone serious focus issue trump voice skepticism u.s. military involvement abroad past first time say america effort islamic state militants might require 20,000 30,000 u.s. troop number similar republican hawk propose cnn-hosted debate university miami crucial come days vote florida ohio determine whether u.s. senator marco rubio florida ohio governor john kasich able continue increasingly long-shot candidacies previous assault trump fail knock rubio u.s. senator ted cruz texas choose civil approach raise question trump policy position without attack personally trump part use debate try attract establishment republicans say generate support non-republicans could help carry party victory nov. election eschew inflammatory personal attack rival draw cheer boo prior debate republican party great chance embrace millions people never know come millions seize opportunity say stick position many establishment republicans reject belief state television interview followers islam hate us serious problem hate tremendous hate say trump propose temporary ban muslims enter unite state rubio cruz kasich say unite state need maintain good relations muslim countries middle east help fight islamic state militants go work people muslim faith even islam face serious crisis within rubio say rubio also defend american muslims patriots go anywhere world go see american men women serve us uniform muslims say anyone uniform unite state will die country someone love america add rubio shift positive tone anti-trump tirades past two weeks cruz repeatedly seek raise question trump policy position trade middle east cruz point areas trump late-comer conservative movement past support democratic cause candidates also note trump ask supporters rally demonstrate support raise right hand scene produce photograph critics say look like nazi germany donald rally recently take ask people crowd pledge support say think exactly backwards pledge support way around cruz say trump discuss would consider place 20,000 30,000 u.s. troop grind defeat islamic state militants vow complete mission quickly bring troop home focus rebuild unite state really choice knock isis trump say would listen general hear number 20,000 30,000 detail view yet trump think islamic state previously talk knock hell isis without offer specifics next tuesday florida ohio republican primaries award delegate winner-take-all basis mean winner popular vote award state entire slate delegate far 25 state puerto rico hold nominate contest trump amass solid lead delegate race accord associate press trump 458 delegate follow cruz 359 rubio 151 kasich 54. clinch republican nomination require 1,237 delegate total 367 delegate stake tuesday include total 165 florida ohio trump thursday appear try appear presidential something pledge often past never thursday modulate tone voice tenor remark prior debate draw sharp criticism vulgar would say together go come solutions go find answer things far believe civil trump say two-hour debate include sober discussion press foreign domestic policy challenge include illegal immigration reform social security free trade deal role federal government education israel additional report ginger gibson alana wise amanda becker write steve holland edit leslie adler article fund part sap independently create reuters editorial staff sap editorial involvement creation production trump 's islam comment draw attack republicans discover civility