If Hatch takes over the AG slot, it will be for four years and he will retire from public service at the end of it.
If he doesn't take over the AG slot, then he remains in the Senate (and on the Judiciary Committee) for two and very possibly eight more years, authoring legislation with Ted Kennedy and compromising with liberals to put justices on the SCOTUS in the mold of Ruth Bader-Ginsberg (which appointment Hatch boasted of in his biography).
Which scenario do you prefer?