FAIRFIELD, Calif. — Republican leaders and voters, frustrated by their party's prolonged presidential contest, are increasingly coalescing behind front-runner Mitt Romney. Yet Rick Santorum on Thursday urged conservatives not to forsake their principles under pressure. He did so by conjuring the memory of Ronald Reagan, still the conservative icon, at an oddly symbolic place: the jelly bean factory that created the former president's favorite treats. "Let them know, conservatives all across this country have not given up the fight, we're not going to concede to the moderate establishment who wants to convince everybody that it's over, it's time to go...