In party terms, Haiti has reversed traditional line-ups on the use of force. This time the Republicans, who cheered the Gulf war and the interventions in Grenada in 1983 and Panama six years later, flatly oppose doing the same thing in Haiti now. Where support exists, it is mostly among the liberal Democrats, who voted against Operation Desert Storm.
In fact, Mr Clintons's own party is divided three ways. Conservative Democrats broadly agree with Republican arguments that Haiti is not worth a single American life and, that once in, the US military will find it very difficult to get out. In the middle is a group that wants to give the sanctions that already exist a chance to topple the army- backed regime.
Backing for an immediate invasion is limited to two segments of the party: its liberal wing, above all the overwhelmingly Democratic black caucus in Congress whose nearly 40 House votes Mr Clinton desperately needs for the passage of initiatives such as health care, and Democratic politicians such as Senator Bob Graham of Florida, who come from states where Haitian immigrants, legal and illegal, tend to end up.
Hence one of the few clear aspects of zig-zagging Washington policy-making on Haiti, now conducted almost exclusively from the White House. If the US does go in, the true reason will not be outrage at the brutalities of the military regime, nor an overwhelming fondness for the ousted President, Jean-Bertrand Aristide, whom many US officials privately hope will lose the next election, theoretically in 1995. The driving motive is the flood of would-be immigrants from Haiti.
Even before the latest Haiti crisis, illegal immigration was so straining Florida's finances that the state is suing the federal government for dollars 1bn ( pounds 650m) of assistance it says it has been denied. Other states are doing the same.
For Mr Graham, the only way to deal with the problem is at its source. For the black caucus, the determining factor is racial discrimination. Their objections that predominantly black Haitians were being treated far more harshly than illegal white immigrants, not to mention Cubans who are automatically granted asylum, forced the Clinton administration to relax the repatriation rules for Haitian boat people.
The result was an almost unmanageable increase in immigration, harrowing television pictures of desperate Haitians being rescued from sinking, overcrowded boats by US coastguards, and yet more pressure on the administration to act. For Mr Clinton there is also personal experience: the problems with Cuban refugees assigned to camps in Arkansas which were a factor in his defeat in the 1980 Arkansas governor's election.
None of this, however, has made much impression on the public. Polls show most Americans oppose military intervention. But that could change if US citizens in Haiti come under threat or if egregious human rights violations by the Haitian authorities come to light.