From a piece in the "Week in Review" section of today's New York Times:

Many experts and members of both parties say they worry about the long-term consequences of such bitter partisan polarization and its effect on the longstanding tradition — although one often honored in the breach — that foreign policy is built on bipartisan trust and consensus.

“The old idea that politics stops at the water’s edge is no longer with us, and I think we’ve lost something as a result,” said John C. Danforth, a former senator and an ambassador to the United Nations under President Bush….

Democrats say the Republicans repeatedly broke the old rules, treating national security as a wedge issue to make Democrats look weak and unacceptable, especially in 2004. “George Bush decided to make foreign policy partisan in a way that Ronald Reagan or the first George Bush never did,” said Senator Charles E. Schumer of New York, chairman of the Democratic Senatorial Campaign Committee.

Representative Rahm Emanuel of Illinois, the chairman of the Democratic Congressional Campaign Committee, said, “The divisions over Iraq and national security are the house that Karl Rove and George Bush built.”

“Politics stops at the water’s edge” hasn’t been true for many years. The 1980 election, for example, was dominated by the economy and national security. Jimmy Carter warned voters that Reagan was a dangerous man to elect in a nuclear-armed world, while Reagan accused Carter of weakness in the face of Soviet expansionism. Once in office, the majority of Democrats fought against Reagan’s national security polices. There was a bitter ideological divide on Central America and Reagan’s buildup-build down approach to the Soviets. Walter Mondale, Edward Kennedy, John Kerry and many other Democrats pushed the nuclear freeze and the notion that America was less secure under Reagan’s leadership. In fact, in his announcement speech for president, Mondale said he was running “not just to seek a victory, but to point toward sanity. “Mindless, wasteful madness” is how he characterized Reagan’s nuclear policies. But despite vocal Democratic opposition, Reagan was able to score many legislative victories on security issues with the help of something that is in short supply in today’s Democratic Party -- Scoop Jackson Democrats.

Today, the one Democrat who most embodies that tough-minded spirit (a spirit embraced by Sens. Dole and McCain on Kosovo), Sen. Joe Lieberman, is being purged from his party and woke up this morning to read an editorial from the nation’s most prominent liberal newspaper endorsing his primary opponent – the darling of Moveon.org.

And with all due respect to Sen. Schumer and Rep. Emanuel, once it become clear that wmd stockpiles were not going to be found, Democrats – see here and here – were happy to use Iraq as a political issue against the GOP.