There is a still a path for Jeb Bush, but it appears considerably more narrow and treacherous. He needs to destroy Marco Rubio or for him to prove unsuitable in some way, hence his team’s obsession with Rubio and the talk of how big its Rubio oppo file is. (Usually campaigns just use their oppo file, rather than talk of how extensive it is; for its part, the Rubio team seems quite confident there is nothing new out there–but you never know.) Then, Bush needs Kasich and Christie to get no traction, which is certainly possible. Then, he needs Cruz or Trump (preferably Trump, which is why the campaign’s attacks on him have been strategically ill-advised) to emerge out of the populist wing as a major threat for the nomination and for enough of the party to turn to Bush as the only plausible vehicle in a stop-Cruz or stop-Trump movement. This would probably mean intra-party warfare made all the more vicious by the fact the Bush stands for everything the populist-wing hates. Having secured the nomination, Bush would then have to try to rally more or less embittered Trump or Cruz supporters to his banner. Maybe this scenario is too grim and Bush will get stronger in a way he hasn’t to this point, but if if this is indeed Bush’s path, the last word you would associate with it is joyous.