WASHINGTON (AP) — The Republican presidential candidates sound much alike in their zeal to shrink government, cut taxes and replace President Barack Obama’s big health care law with, well, something entirely different. It takes some digging to see the distinctions.

That’s when Mitt Romney, for example, emerges a few steps removed from the deeply conservative drift of the pack. Sure, he says constitutional abortion rights should be overturned. But unlike Michele Bachmann and some others, he’s not up for clashing with the current Supreme Court over it. Yes, he wants to sweep away regulations that interfere with business. But unlike the slashers and burners, he wants the rules to be “updated and modern,” not thrown as a heap in the trash.

Altogether, it’s a familiar pattern on the cusp of party primaries. The candidates play to their ideological base so hard that true differences among them are blurred. The presumed favorite caters to the same crowd without getting locked into positions that might prove a disadvantage with the broader and more moderate electorate next fall.

That pattern results in an array of positions that sound good to the true believers but have little or no chance of becoming law. And it can produce flat-out contradictions.

Witness Herman Cain’s assertions that no abortions should be allowed — and that the government has no business telling a woman she can’t have one. Or the position of several candidates that gay marriage should be outlawed in the Constitution — and that states should be allowed to legalize or prohibit it individually, a right they would not have if the Constitution were so amended.