Over this past week, there has been a strange phenomenon at play in the Republican presidential race.
Exit polls from the flood of Super Tuesday primaries indicated that late-deciders moved against front-runner Donald TrumpDonald TrumpTrump's environmental order jeopardizes our national security Republicans vote to block resolutions on Trump's tax returns DNC asks entire staff for resignation letters MORE. A comparison of pre-primary polls to the actual ballots cast on March 1 showed clear evidence of Trump's eleventh-hour slippage: The last two polls taken in Virginia gave Trump an average 14 percentage point lead. On primary day, he won by a mere 3 points. The last two polls in Oklahoma gave Trump an average lead of 13 points. In actual voting, he lost by 6 points. The last three polls taken in Texas gave Cruz an average lead of 5 points. On primary day, Cruz beat Trump by 17 points.
Why is this? Is it because something new — or perhaps the accumulation of ongoing attacks — is giving Trump's supporters last-minute second thoughts? Is it because Trump wo't spend enough of his own money to keep up with opposition spending in state contests? Or is it that Trump's lack of a ground organization is hurting his ability to turn out voters?
Fans and detractors can debate the causes, and may decide it's a mixture of all of them. But for Trump, if this phenomenon continues today in Michigan and through March 15 in states like Florida, Ohio, North Carolina, Missouri and Illinois, it could seriously hamper his ability to lock up the nomination any time soon.
At this point for a presidential front-runner, you have to look at the rolling delegate count. After Super Tuesday, Trump had 47 percent of the total pledged delegates. Now, after Saturday's contests, he has 44 percent.
You also need to remember that Trump is now running against not just opposition candidates, but a number: the 1,237 delegates he needs to win the nomination. With 21 states accounted for, he has 384 delegates. The New York billionaire needs to win 54 percent of the remaining delegates to secure the nomination.
Donald Trump remains the clear frontrunner. But if this last-minute slippage doesn't stop, his advantage becomes less clear.
Faucheux is president of Clarus Research Group, a nonpartisan polling firm based in Washington. Author or editor of seven books, including "Running for Office," he also publishes LunchtimePolitics.com, a daily newsletter on polls.