I like the Biden choice from many angles. Looking at the synastry between Biden's chart and the Sag rising USA chart, we see that Biden's retrograde Jupiter, his chart ruler, conjuncts the USA Mercury, opposing the USA Pluto. That USA Mercury-Pluto opposition in Cancer/Capricorn, is key to our foreign affairs and holds for any July 4th, 1776 chart, no matter the rising sign. It points to Biden's valuable length of tenure in the Senate handling judicial and foreign affairs, both 9th house matters.
Biden's birthdata: 11/20.1942, 8:29 am, Scranton, PA. See astrodatabank.com for the USA chart.
I love Biden's tough Scorpio Sun with its combust Venus which explains his magnetism and affectionate Irish geniality. This Sun/Venus/Merc. conjunction trines his n. Jup. and USA's n. Merc. His Mars, also in Scorp., trines the USA's Jupiter/Venus, again bringing in that vociferousness he's known for, yet the joking, appealing side. Some were shocked at his lugubriousness at judicial hearings. But he's obviously at home wielding power in his own way.
The lack of strong harmonious Moon interaspects shows why Biden couldn't win two Presidential bids [Michael O'Reily argues that it's all-important for Presidents to connect to the USA Moon at 27 Aq., thus appealing to the public and capturing the vote]: Biden's Moon in Taurus squares the USA Pluto in late Cap. though it sextiles the USA Venus in Cancer. His only Ptolemaic [major] aspects to the USA Moon are squares from his Sun/Ven. Those interaspect squares in fixed signs show that we will see even more of his some say principled, others say irascible side in the future. He's not going to bite his tongue--ever. Presidents have mouthy veepees-remember Spiro Agnew? The job is a perfect place for attitude, and, of course, the campaign trail calls for a v.p. attack dog.
Another interesting interaspect that echoes Obama's Neptune close contact with the USA chart is the USA Neptune sitting on Biden's Midheaven with his own Neptune not far away in the 10th house of prominence. Inspiration, inspiration, inspiration is the hallmark of Neptune. You gotta get people inspired to get them out of their mundane worlds and to the polls. To the t-shirt wearing stage. To the participatory democracy stage. I'd like to see how McCain tops this.
Biden's retrograde Pluto is exactly conjunct the USA North Node, a mark of destiny, and promises transformation and regeneration which the country needs badly. The charts' Saturns are trine in air signs, lots of communication and plans made through agreements and talks. Looks like Biden will be a veep-ambassador more than most. No Cheney-in-the-bunker type here.
Pardon my bias. I have the Sun in Cancer right on Biden's Jupiter; my Moon in Pisces trines his Scorpio planets. Biden's long political career speaks to his strong Saturn, conj. Uranus, at his 7th house angle, his Descendant. It points to the tragedy that occurred one month after winning his Senate seat and losing his wife and infant in a car-train collision. Yet he rebounded, Scorpionically, and went on to become Delaware's longest serving senator. I know the power of water strength in a chart. It can wear away the rock every time. It just takes time.