Sen. John McCain, R-Ariz., has signed on to a new bill to be introduced Friday by Sens. Kirsten Gillibrand, D-N.Y., and Susan Collins, R-Maine, to block President Trump's order to ban transgender military service, according to two congressional aides. The stand-alone bill, which is also co-sponsored by Sen. Jack Reed, D-R.I., the top Armed Services Democrat, has the same language as an amendment proposed by Gillibrand and Collins this week for the National Defense Authorization Act that would prohibit the military from barring service based on gender. That amendment never received a floor vote due to a dispute between Republicans...