Most initial polls were performed before Jeb’s actual announcement. The latest polls are measuring his impact since that date. At the time, he was behind both Rubio and Scott Walker. These candidates have serious flaws, and Jeb has always been seen as the only credible candidate. Scott Walker is a college dropout, and Rubio was never a serious candidate. It is the lack of credible candidates that would spur another Bush to run for the republican candidacy. However, Jeb has dominated the nightly news cycle even with a crowded field that includes people like Donald Trump. Upon Trump‘s announcement, he was seen as a threat for many of the other lesser known republican candidates because of the format that is used to determine which republican candidates will be able to participate in their primary’s debates.
However, since his announcement, Trump has lost almost all of the initial steam. He now polls near the bottom of the pack. This is a relief for many establishment republicans that see Trump as significant distraction because of his flamboyance and rhetoric. Candidates like Trump were widely blamed for many of the losses that prevented republicans from obtaining the Senate much earlier. The establishment forces have mobilized against many of their efforts to drag the Republican Party severely to the left since those mid-term fiascos. The establishment’s control of the party has been bolstered by their successes from what Brad Reifler suggests.