( CNN ) -- Hillary Clinton 's book roll-out the past few days has shown , as expected , that she still commands an army of rapturous fans , but the best news for her this week came from the completely unexpected : the defeat of Republican leader Eric Cantor . Rarely has a GOP primary for a seat in the House of Representatives had such wide repercussions . For Clinton , they almost all run in her favor . Consider just three : . ( 1 ) Prior to the Cantor defeat , the GOP `` establishment '' thought they were starting to persuade middle-of-the-road voters that their party is not hostage to the tea party . After all , GOP establishment candidates so far this year have won five of seven Senate primaries where they were challenged by tea party candidates , most notably Mitch McConnell 's victory in Kentucky . A public narrative was emerging that tea partiers remained a potent and , yes , welcome force in the GOP but that they are n't in charge . The defeat of Cantor was a thunderclap transforming the landscape . Because Cantor is perceived as a strong conservative , and yet lost to an unknown on his right , the narrative has changed : Now the story line is that the GOP base is not only angry but demands even tougher conservatism and even less compromise . All this plays directly into Clinton 's hands . If she formally declares , she can now stand before the electorate and assert with greater credibility that she -- not the GOP -- represents sensibility and moderation , a leader eager to work across the aisle . She even has greater latitude to embrace some of Elizabeth Warren 's positions , appealing to the rise of a populist left , so long as she does n't veer too far from the middle ( where most voters still are ) . ( 2 ) Cantor 's defeat all but extinguishes lingering hopes that Congress and President Obama can work out a bipartisan agreement on immigration reform . Two post-election polls have suggested that Cantor 's perceived openness to immigration reform was not the decisive factor in his defeat , but his opponent certainly seized on immigration as a stick to beat him over the head as an out-of-touch , wrong-headed reform advocate . In the wake of his defeat , it 's hard to see how other Republican incumbents will follow Cantor 's path . And for starters , they will likely be very wary of voting for immigration reform until dust settles . That , of course , is bad news for the GOP presidential nominee in 2016 and good news for Clinton if she is the Democratic standard bearer . Mitt Romney could only garner 27 % of the Hispanic vote in 2012 , far below the 40 % that pundits think is mandatory for victory . Unless it finds a way out of the cul de sac , the GOP share could sink even lower this time . Opinion : Should Clinton embrace Obama 's foreign policy ? ( 3 ) We have n't yet heard from that corner , but one can only imagine that the Cantor defeat , tied so closely to charges that he was for `` amnesty '' for illegal immigrants , is prompting second thoughts by Jeb Bush and his many admirers about whether 2016 is the right year for him to run . If Bush 's deep belief in immigration reform would tear apart his party in the primaries and make his path to the White House perilous at best , why should he ? If Jeb Bush decides not to go , that would be extremely welcome news to the Clinton camp . From the point of view of Democrats , the most obvious threat to a Clinton victory is a Republican governor conservative enough to unite his party but moderate and experienced enough to pull in purple states . Jeb Bush and Chris Christie are the two who come closest to that profile . Conservatives may disagree -- many genuinely believe that a Rand Paul can win -- but Democrats will quietly celebrate if neither Bush nor Christie tops the Republican ticket . It is an oddity of American democracy that a tiny number of voters -- fewer than 8,000 -- in a suburb of Richmond , Virginia , can substantially alter the national outlook . But we live in odd , unpredictable times . No doubt other big surprises lie ahead before November 2016 .
Hillary Clinton gets a gift from the Republicans as she rolls out her book . David Gergen says Eric Cantor 's defeat is a big plus for Clinton if she runs in 2016 . He says it diminishes the chance that she would face a GOPer with appeal to moderates . Gergen : By placing immigration reform in jeopardy , the upset hurts GOP 's 2016 appeal .