For all the hype surrounding the Feb. 1 caucuses, only a fraction of Iowa's registered voters participate.
So over the final weekend, campaigns on both sides of the aisle were focused on turning out voters.
But the one question the polls or the crowds or the pundits can't fully answer is just how many people will show up Monday? And what will the numbers mean?
Most Republicans expect a higher turnout in 2016 than the last two caucuses, when about 120,000 showed up. Democrats doubt they will match 2008, when nearly 240,000 came out.
The higher the turnout, the better the outcomes could be for businessman Donald Trump on the Republican side and Vermont Sen. Bernie Sanders on the Democratic side. Both are seeking to get nontraditional participants out.