There will be a transit of Mercury across the Sun November 8, just in time for the US elections. This is a different event than a simple conjunction of Mercury and the Sun; it is more like an eclipse where we are actually able to see Mercury silhouetted against the disk of the Sun. See the NASA site for the technical information. There are only thirteen such transits of Mercury in a century so they are a relatively rare event. The last one occurred in 2003, and we won’t see another until 2016.
Transits of Mercury occur at the midpoint of the Mercury retrograde period and because eclipses tend to mark crisis points that instigate change, we may notice a shift in focus at that time. The last Transit of Mercury occurred May 7, 2003 and during the following week there were two suicide bombings in Chechnya, a bombing in Riyadh Saudia Arabia, and a suicide bombing in Casablanca. In addition, the week of May 4 through May 10 marked a period of 393 tornadoes in 13 US states, more than during any period in US history. At the time Mercury was locked in a stressful T-square formation with Mars and Jupiter that no doubt had an influence on the week’s events.
The previous Transit occurred November 15, 1999 (these events always take place in either May or November) and was not associated with any major events such as this. At that time Mercury did not make any stressful aspects. The chart for the upcoming Transit event on November 7 is very complex, and occuring one day after the US election I would expect some sort of major political crisis.
(Geeky astrological details: We have five planets lined up in Scorpio within 16 degrees: Mars, Sun, Mercury, Venus and Jupiter. Jupiter is still within range of its final square to Saturn and the Sun/Mercury/Venus are tightly square to Neptune. The Moon opposes Pluto exactly that day, Saturn and Neptune are still within range of their opposition as well. This is a volatile mix.)
Those of you wishing to research the historical significance of the Transit of Mercury more extensively may want to check out the Seven Century Catalog showing transits of Mercury since 1601. Also, safely watch the webcast the day of the transit at this site (thanks to John & Susan Townley for the link!).