The New York Times reports today — based on unclear sourcing — that Mitt Romney has endorsed a strategy of raising doubts about Newt Gingrich’s “emotional stability.”

Well, if that’s the case, here’s Exhibit A.

A Florida source passes along a mailer that the Romney campaign — not the pro-Romney Super PAC; his campaign — just dropped in the state, and it comes as close as possible to making that case, hitting Gingrich as “erratic” and “reckless.”

The mailer also prominently features a quote from my colleague Jennifer Rubin, describing Gingrich’s “well of sleaze.” Here’s page one:

And here’s page two:

This the sort of attack that’s probably too hot for the Romney campaign to be directly associated with on the airwaves, which may explain why it’s being pushed via mail, which is relatively under the radar.

The mailer underscores the lengths the Romney campaign is now willing to go to in order to destroy Gingrich’s character, after aides had previously congratulated themselves for mostly sticking to the issues. It suggests the Romney camp knows how dangerous a Gingrich victory in Florida — where the two are deadlocked in polls — would be to Romney’s long term hopes.

The Times observes that Romney’s new strategy of tearing down Gingrich’s character risks turning off the independents, women and suburban Republicans that Romney will need in a general election. As the above mailer suggests, it’s a risk the Romney team is prepared to take — and perhaps sees as an imperative at this point.