5th paragraph says "Trump should have lost by 9 points given the difference between Obama"

Q1: In order to achieve what, should Trump have lost by 9 points?

Q2: Trump competed with Hillary. Why does it say "given the difference between Obama"??


Context>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
The political future of President Donald Trump and the Republican Party over the next two years really comes down to one question: Do traditional measures of popularity mean anything when it comes to Trump?

If they do, the Republican Party and Trump could be in major trouble.

Usually, we wouldn't even think to ask whether a president with around a 40% approval rating would end up hurting his political party. Yet Trump did something that was seemingly impossible in 2016: He won the presidency, despite being the most unpopular candidate since at least 1952 and with Americans seeming to like the status quo.

President Barack Obama's net favorability rating in the final Gallup poll using a -5 to +5 scale was +16 percentage points. Trump came in with a -25 percentage point net favorability rating in the same scale. That 41-point difference should have been electoral poison for Trump.

Based upon Gallup polling from the previous six presidential elections without the incumbent running for reelection, Trump should have lost by 9 points given the difference between Obama (the incumbent president) and Trump's rating. He only lost the popular vote by 2 percentage points and won the Electoral College, however.

Although six data points drawn from previous elections without an incumbent running are a far smaller sample size than I would like, the clear separation between 2016 and what previous years predicted makes it pretty clear that something unusual happened in 2016.

The easy answer is that elections without the incumbent running are also about the candidates who fill the shoes of the incumbents on their party's presidential tickets. In this case, Hillary Clinton was also very unpopular. In the network exit polls, Clinton had a net favorability rating of -12 percentage points to Trump's -22 percentage points. This made for the first presidential election in polling history in which both candidates were disliked by more voters than they were liked.