Participating in a nasty penis joke about a presidential candidate doesn’t align with the Society of Professional Journalists’ Code of Ethics. It reflects reportorial immaturity and possibly even bias toward the candidate in question.

And Politico reporter Joe Williams stands accused of the infraction as of last night. A piece on carries some embedded tweets from Williams’s Twitter handle — @jdub321. Specimens include one in which Williams re-airs a tweet using dirty inferences to malign Republican presidential candidate Mitt Romney and his wife, Ann.

That retweet, together with others and a Thursday MSNBC appearance in which he suggested that Romney was comfortable only with white people, prompted Politico last night to suspend Williams pending a review of his record.

One thing, though: Williams isn’t conceding authorship of that Twitter activity. “That tweet abt Ann Romney — it’s really offensive and I don’t think I retweeted it. I may have been careless but I’m not stupid,” he says via e-mail. Williams is checking his feed to see if he’s indeed responsible.

It’s hard for outsiders to check for themselves at this point, since Williams has locked down his Twitter account so that only his 800-plus followers can see his timeline. However, one such follower provided a glimpse of Williams’s feed. A tweet from April 2 matches the penis-joke tweet highlighted by