George W. Bush's presidency ended on a very sour note. His approval ratings dipped into the 20s as the Iraq war dragged on and the financial crisis hit. When Americans were electing his successor in November 2008, 7 in 10 of them disapproved of the outgoing incumbent.

This is how bad it was:

Eight years is a very, very long time in politics.

The latest Gallup poll, in fact, shows Bush with pretty strong image numbers, as politicians go these days. A majority -- 52 percent -- now view the former president favorably, while 43 percent view him unfavorably.

In fact, being out of the political game -- Bush is even sitting out this week's Republican National Convention in Cleveland and declining to back Donald Trump -- appears to be very good for his image.

How do we know that's likely the cause? Well, presidents historically have almost always seen their image improve after leaving office. Not being in the news or engaged in the heated political debates of the day makes people more nostalgic for you. They remember the good times and forget -- or at least forgive you for -- some of the bad.

Also proving that point? The fact that Bush is now about as popular as his predecessor, Bill Clinton.

As Hillary Clinton's presidential campaign has drawn on and her own numbers have dropped badly, the former president has seen his image take a hit too. A Quinnipiac University poll in May showed his favorable rating at 48 percent, while a CNN poll last month showed it at 51 percent -- down from a high of 66 percent as recently as 2014.

Bill Clinton's presidency, we would note, is generally much more well-regarded than Bush's. While Clinton certainly had his problems -- many of which are being rehashed even as I write this -- his presidency featured good economic times and is generally viewed as a success. During their second terms, Bush's average approval rating was 36.5 percent, per Gallup. Clinton's was 60.6 percent.

And yet, here we are in the heat of the 2016 campaign, and Americans (at least for now) view Bush about as positively as Clinton.

Let this be a lesson to you all: If you want to be liked, stay far, far away from politics -- and especially Donald Trump and Hillary Clinton.