In some ways it's a shame political questions can't be approached like scientific experiments, controlling all other factors in order to test one hypothesis.
In a perfect world, the question of whether an abortion rights candidate could win the 2008 Republican presidential nomination would be settled by running an attractive, intelligent candidate who was well within the mainstream of the Republican Party on all other issues and who had no significant personal or professional baggage weighing him down.
If that were possible, then the proposition could be properly tested. Obviously, the subject in question is former New York City Mayor Rudy Giuliani, who tops several national polls for the Republican presidential nomination.
However, the subject could also be former Massachusetts Gov. Mitt Romney, who took the abortion rights side of the issue until a few years ago, when he switched to being an anti-abortion rights candidate, he says, because of a change of heart while studying the issue of stem cell research. In Romney's case, the question is whether having once favored abortion rights is a disqualifier. Furthermore, there is obviously a second issue of whether he made the switch on this issue or others simply for political expediency.
That is a different question entirely -- more one of character, or whether a politician is allowed to have a change of heart -- than of substance.
Could it be that there is a silent majority of abortion-rights or secular Republicans who would rise up and assert themselves in the 2008 GOP nomination process? Or maybe this group's numbers would be added to by nominally anti-abortion rights or ambivalent Republicans who simply choose to select their nominee on the basis of a broader range of issues.
Also, as in the case of Giuliani, voters might be particularly drawn to that candidate's strength in other areas, such as his reputation for courage and strength in the aftermath of the Sept. 11, 2001, terrorist attacks. That's plausible. The problem is, abortion isn't the only keynote social or cultural issue that Giuliani runs into problems with Republicans on.
Questions about Giuliani's divorces and how he has made a living since leaving the mayor's office complicate the equation, making his future anything but a clean test on whether abortion remains a critical litmus test issue for GOP presidential contenders. If Giuliani were to fail to secure the nomination, it would be unfortunate having no definitive political autopsies to establish the precise cause of electoral death.
Then again, if he were to succeed, it would mean he did so despite a closet filled with baggage, and it would truly be an impressive victory for that reason.
This is a critical juncture for Giuliani.
While he remains on top by some measurements, there could be signs that his lead is in jeopardy. University of Wisconsin political scientist Charles Franklin has his own Web site on polling, Political Arithmetik, and partners on a second site, pollster.com.
These are two must-visit sites for those fascinated with political polling.
On both sites, Franklin regularly publishes updated graphs of his "trend estimator," something more sophisticated than, but similar to, a moving average showing the relative strengths of each presidential candidate in recent national polls.
The indicator published on both, which he nicknames "Old Blue," reflected in blue lines on the graphs, indicates that Giuliani has about 33 percent of the GOP vote, Sen. John McCain is second with 20 percent, former Sen. Fred Thompson third with 13 percent, followed by Romney with 9 percent and former House Speaker Newt Gingrich, R-Ga., with 8 percent.
This trend estimator covers quite a few national surveys and is extremely reliable.
When it shows a candidate's support level rising or falling, you can pretty much take it to the bank that it is happening. Its shortcoming is that because it encompasses quite a few polls, it is a bit sluggish, and slow to catch some changing trends. The good news is that this indicator gives very few false signals.
On Franklin's more technical (read geeky) site, he publishes another set of graphs, including the "Ready Red," a far more sensitive indicator that places more emphasis on the most recent polls.
It is quick to show changes in trends, but has the downside of being susceptible to reporting false positives -- indicating trend changes that turn out not to be the case.
Using that more hyperactive "Ready Red" measurement, Giuliani's lead peaked in February and has dropped steadily since, while McCain's nosedive is shown to have turned back up in March or early April.
So, while "Old Blue" shows Giuliani with a clear lead on McCain, "Ready Red" has a tightening race.
Obviously there is an enormous amount of time between now and when voters begin casting their ballots early next year, and there are a multitude of factors to consider besides national polls.
But polls are a measurement of momentum and do have an effect on fundraising. Furthermore, they help shape the public and media perceptions of the race. Keep an eye on the next month of polling and, depending upon your point of view, handicap with either "Old Blue" or "Ready Red."