You may not, however, be familiar with Josef Wagner.
Wagner (1899 - 1945) was an early member of the Nazi Party in Germany, serving as Gauleiter (a paramilitary rank appointed directly by Hitler himself -- comparable in many respects with being Governor of a state or province). Wagner was a member of the Nazi Party early on, in 1922 (as a 23 year old man). He was later dismissed by Hitler due to his wife's reluctance to see her daughter marry an SS officer.
A star within the Nazi Party, Wagner was expelled from the Party in 1942 and later, after the failed attempt on Hitler's life on July 20, 1944, he was arrested by the Gestapo. Wagner died in 1945, either at the hands of the Gestapo or, possibly, Soviet soldiers who overran Berlin as the war in Europe came to a close.
So Wagner was a Nazi bigwig who ended up on the outs . . . for more about Josef Wagner's life here is a link to his Wikepdia entry: https://en.wikipedia.org/wiki/Josef_Wagner_(Gauleiter)
the most important piece, ultimately, is Astrology.
We have a time of birth for Breitbart but do not with Josef Wagner, so I used Astrodienst to create a chart for a birth time of Noon. Therefore we can't determined Wagner's Rising Sign nor the exact placement (and sign) of his Natal Moon. However, were Wagner to have been born in the afternoon, his natal Moon would have been in the early degrees of Aquarius, forming an exact opposition to Breitbart's at 1 Leo.
Wagner was born immediately following a New Moon, Breitbart just before the Moon was Full.
Are there any planetary placements that jump out as being potentially #significant. Actually, there are -- or I wouldn't be posting this as a possibility.
Breitbart has Venus at 29 Pisces parked on his Ascendant (27 Pisces) and opposing his natal Pluto at 24 Virgo. Wagner has Mercury at 29 Sagittarius forming a tight T-Square with Breitbart's Ascendant / Descendant and also squaring (within one degree) Breitbart's Venus. Wagner's Mercury is in a loose opposition with his natal Neptune (22 Gemini) and even though this is a 6 degree orb, it ties in closely with Breitbart's Pluto, which it squares.
In essence, two oppositions forming a Grand Cross, accentuated even more greatly due to the Ascendant / Descendant axis.
Wagner had Mars Retrograde in his chart at 1 Leo, conjuncting Breitbart's natal Moon at 3 Leo (which opposes his natal Mercury at 5 Aquarius); again, if Wagner was born in the afternoon, his natal Moon would have been in early Aquarius and opposing his natal Retrograde Mars -- not such an easy aspect, one might think.
Both men had a tight conjunction, as well, of another planet with their natal Uranus. Wagner has both Venus and Chiron conjunct his Uranus and Breitbart has Uranus conjunct Jupiter and his South Node. Breitbart's NORTH Node also conjuncts Chiron, so opposes Jupiter / Uranus.
Sun / Pluto interchanges are common (again, according to my "theory") in past life matches and Wagner's Pluto (14 Gemini) forms a Trine aspect with Breitbart's 12 degree Aquarius Sun. To return the favor, Breitbart's Pluto at 24 Virgo also forms a Trine with Wagner's Sun (22 Capricorn).
Combined with the striking physical similarities between the two of them (as well as my belief that Breitbart's successor, Steven Bannon, may have ALSO been a Nazi Gauleiter -- Carl Rover)
I believe Andrew Breitbart is the reincarnation of Josef Wagner