“It truly frightens me to think what’ll happen if Mitt Romney is the nominee,” says the letter signed by Santorum and paid for by his campaign.

The undated letter says there’s still time for conservatives to make sure the GOP doesn’t nominate “a Massachusetts Moderate” and that Republicans would be “crippled” if Romney were to become the nominee.

The blunt message quickly had Republicans here speculating: Did Santorum order up the mailer right before he suspended his campaign on April 10, so its timing was just a simple and understandable mistake? Or, did Santorum, who is still raising money and possibly not quite ready to come to grips with his loss, send this wording out deliberately?