A president can't but Romney will be attacked here anyway by the usual suspect.
Even the GOP platform acknowledges this simple truth by calling for "life amendment" to the constitution and presidents have no formal role in the amendment process.
Yes, you have that absolutely right, people like muawiyah have one goal here, to make sure that Obama is President when sickly Ruth Bader Ginsburg who will be between 80 and 84 years old, leaves the court knowing that if Romney and Judge Bork pick her replacement that young constitutional conservative will join Antonin Scalia, Anthony M. Kennedy, Clarence Thomas, Samuel Anthony Alito, and John G. Roberts as the crucial 6th vote. That is what all this trollism is all about and never forget it. They will be in attack mode (from the right) every single day to keep abortion safe, legal and affordable.