The pollsters say it’s up for grabs. So both sides know that these are the three most important factors in today’s 1st Congressional District special election between Mark Sanford and Elizabeth Colbert Busch: Turnout, turnout and turnout.

This race has attracted considerable attention in and beyond the district and state. It has also stirred some hard feelings.

But if you’re a 1st District registered voter, and you want to have a say in who represents you in the U.S. House for the next year and a half, it’s now your turn to choose.

More than 290,000 people voted in last November’s 1st District House election.

Less than a quarter of that total voted in the March 19 primaries to pick Tim Scott’s replacement — fewer than 55,000 in the Republican primary and fewer than 17,000 in the Democratic primary. Then on April 7, fewer than 47,000 voted in the GOP runoff.

Sure, the 2012 1st District contest was part of a presidential general election, and thus bound to generate a large turnout.

Yet today’s election to pick South Carolina’s next member of Congress should rate a big crowd of voters, too.

This House seat came open after Gov. Nikki Haley appointed Mr. Scott, who had won a second term mere weeks earlier, to the U.S. Senate to fill the void left by Jim DeMint’s resignation.

Today, the many folks who have taken a ballot-box pass — so far — on this spirited contest get a last chance to correct that mistake of omission.

We endorsed Ms. Colbert Busch in Sunday’s paper, citing her impressive background in the business community, her energetic advocacy of economic development in the district and her resolve to work across party lines to advance practical solutions to the pressing problems of our times.

We also recommend, though, that regardless of whether you agree with our judgment in this race, you make your judgment count today.

Our self-governing system depends on a well-informed, actively engaged electorate.

And when you don’t exercise your precious right to vote, you have precious little right to complain about who represents you in the halls of power.