Pat Buchanan to shift emphasis along with party.

WASHINGTON _ Whether out of pique or principle, Pat Buchanan has jolted the political system by talking of bolting the Republican Party to run for president on the Reform Party ticket.

Unable to generate anything approaching the support he gained in his two previous losing bids for the GOP nomination _ highlighted by his win in the New Hampshire primary in 1996 _ Buchanan says his party has abandoned the values and issues he cherishes in favor of the more mushy, indistinguishable middle.

To be sure, many of those issues, such as opposition to abortion, are out of sync with the Reform Party, whose members stress economic concerns and explicitly exclude social ones.

That contradiction hasn't stopped either Buchanan or Reform Party leaders trying to woo him. He says he will merely shift his emphasis, to things like economic nationalism and protectionist trade measures that please the Reform Party faithful.

No matter which course Buchanan chooses, he has almost no chance of winning the general election. But a third-party bid by him could well shape the race. At this point the Republican candidate stands to lose more votes to him, but ultimately the Democrat could be hurt as well.

And in a political culture that has increasingly become a blur of …