Geraldo Rivera announced on Fox News that he's not running for the U.S. Senate. Rivera had previously used his Fox News platform to test the waters for his potential Republican candidacy.

In January, Rivera said on his Cumulus radio program that he was “truly contemplating” running for the U.S. Senate. He then used platforms on Fox News and Fox News Latino to, in his words, “hone a message” for his possible campaign until “it's no longer legal” to do so (a move that drew criticism from media ethicists). Rivera appeared on Fox & Friends and wrote columns for Fox News Latino (see here, and here) to outline his campaign's message and deliver, in the words of Fox host Steve Doocy, his “stump speech.”

Speaking on Fox & Friends this morning, Rivera said that New Jersey Gov. Chris Christie's special election announcement effectively ended the possibility of him running, and said he'll “stay right here” on Fox. Rivera expanded on his decision in a Fox News Latino column, in which he invoked the The Lord of the Rings and Don Quixote.

Had Rivera run for office, he likely would have met the same unsuccessful fate as several other recent Fox News employees-turned-candidates. Rick Santorum and Newt Gingrich won publicity, but not the Republican presidential nomination, in 2012. Angela McGlowan finished a distant third in a 2010 Republican primary for a congressional seat. And Pete Snyder lost his bid to be the 2013 Republican nominee for Virginia Lt. Governor.

While Rivera has taken himself out of the running, Fox News contributors Scott Brown, Allen West, and Liz Cheney still appear to be contemplating future runs for various political offices.