and prayers for those who just found out that they were in a 'failed' marriage and their spouse was moving on to the next one.
Voter registration rolls are made available to congressional offices and campaigns. When I first learned about this in school, that was on 1" tape that the campaign would have to pay to translate to a more usable format, but I assume they're distributing them on CD or DVD by now, or even downloadable via (secure, one hopes) FTP.
Those can be cross-referenced to FEC donor records and commercially available databases, including which magazines you subscribe to. Mack could either blanket every registered voter in his district, or try to narrow the field by including other data. Using grocery and drug store "affinity cards," a campaign could decide if it would rather target people who regularly buy condoms or people who regularly buy diapers.
Depending on the data-handling practices of your state, that might include such things as vehicle registrations; some studies have correlated car makes and models with likely voter behavior, so I wouldn't be a bit surprised if some Democratic campaign somewhere preferentially targeted Volvo and Saab owners while a Republican campaign chased after owners of minivans and pickups.
But, I really don't recall any news "announcement" about a divorce.
No reason there would be. Unless they're sealed, divorce filings are a matter of public record, and reporters could dig them out if they wanted to. Connie Mack isn't a Bill Frist or Tom DeLay, or for that matter a Nancy Pelosi or Harry Reid, so I'd imagine the reporters didn't try too hard.
Half of U.S. marriages end in divorce, a number that skews low in a historical perspective because many "cohabiting," "coparenting" relationships that would have been marriages in years past no longer are. I see no reason to believe that the rate would be any lower among members of Congress; in fact, I would expect it to be somewhat higher, as they spend most of their time apart from their families. I wouldn't expect press releases.
Nevertheless, I wish Connie Mack and Mary Bono well in their new relationship. Life is too short to be miserable and in a failed marriage.
More importantly, I wish their children well. The parents made their choices; the kids were not given a vote. I hope that all the exes and steps remember their love for the folks close to them more than the anger toward people who no longer are. I've seen divorces and blended families that go both ways.