It seems to me the principal needs for a "coattails" political victory include: an overwhelmingly popular nominee, an overwhelmingly unpopular opponent, a historically significant novelty or potential realignment at play and, less interesting but most important, the attraction and activation of an enormous and motivated campaign machine.
Looking ahead to 2008, it's possible we could see a coattails effect on election night, especially in the case of one particular candidate, but given the close division of a 50-50 or 51-49 electorate, I doubt it.
Consider the factors one by one.
1. Overwhelmingly popular candidate. The partisan divide in the United States, a condition that can at times be both a blessing and a curse, means it's unlikely either party will nominate a candidate that huge numbers of the opposition will love.
There's no Dwight Eisenhower or Theodore Roosevelt in this bunch. True, Sen. John McCain (R-Ariz.) has always enjoyed a certain affection among moderate (and even some liberal) Democrats, but in the end, he's just another pro-life, pro-war conservative, and the Democrats flat-out don't agree with him.
Former New York Mayor Rudy Giuliani, if he could get nominated, would certainly garner a lot of support from Democrats, but it's just as likely he would lose at least one conservative for every liberal he gained. Given the current crop of candidates, there's no reason to predict a 55 percent popular landslide for any of them.
2. Overwhelmingly unpopular opponent. Republicans will certainly be hamstrung to one degree or another if President Bush's popularity remains as low as it's been this past year. Depending on how closely tied the Republican nominee is to the president, it could provide a real opportunity for the Democrats, but all the Republican candidates know this and are distancing themselves from the White House.
On the other hand, it's possible that, in the light of public scrutiny, Sen. Hillary Rodham Clinton (D-N.Y.) will prove unlikable. It's also true that Democrats -- even if they don't like her -- want to win and won't easily jump what they see as a very fast, strong ship.
3. Historically significant novelty. On the Democrat side, both Sen. Clinton and Sen. Barack Obama (Ill.) offer historical novelties, as potentially the first woman and first black president. Of the two, I think Sen. Obama has the much greater claim to significance.
Tom DeLay is the former House Majority Leader, the second ranking leader in the United States House of Representatives, and co-author of No Retreat, No Surrender: One American's Fight.