U.S. Sen. Barack Obama’s praise for former President Ronald Reagan is an interesting development, as it is the first time a major Democrat candidate for president has praised Reagan, a Republican whose policies and political success both made him utter anathema to the Democrat Party. Predictably, his opponents for the Democratic nomination for president are attacking Obama as a heretic, illustrating the seriousness of the ideological implications for Democrats.

On Monday Obama told the editorial board of the Reno Gazette-Journal that Reagan made a far greater difference in American society than a couple of other recent two-termers:

Reagan changed the trajectory of America in a way that Richard Nixon did not and in a way that Bill Clinton did not. He put us on a fundamentally different path because the country was ready for it.

I think it’s fair to say that the Republicans were the party of ideas for a pretty long chunk of time there over the last 10 to 15 years in the sense that they were challenging conventional wisdom.

The implicit critique of fellow contender Hillary Clinton’s husband as a trimmer was surely intentional, and both Mrs. Clinton and former U.S. senator John Edwards responded with harsh words about Reagan, echoing an attitude toward him long prevalent in the Democrat Party.

Edwards criticized Reagan for his sins of lowering taxes and refusing to be intimidated by labor unions, and Mrs. Clinton slammed the Republicans in general for shutting down the government (which was actually her husband’s doing) and driving the country into debt.

It is worth noting that Obama did not praise Reagan’s policies directly, choosing instead to cite the undeniable fact that the Republican was successful in his overall attempt to change the direction of American politics and polices. Nonetheless, the extraordinariness of his statement is evident in his opponents’ horrified reaction and the accuracy with which their responses reflect the prevailing sentiments of their entire party over the past three decades.

Talk is cheap, of course, and Obama has shown little to no commonality with Reagan during his brief tenure in the U.S. Senate, but it is an important event when a Democrat presidential candidate praises the most successful Republican president since Calvin Coolidge.