If things had gone according to plan for Republicans, Tuesday's special congressional election for an open seat in Ohio wouldn't be worth your time.

President Trump won this district in the northern Columbus suburbs by 11 points in 2016, and Republicans have held onto it for decades. The election to replace longtime Republican Patrick J. Tiberi, who is leaving for a business opportunity, was supposed to be a relatively undramatic affair.

But despite everything you see on paper, this special election is competitive. That's a boldfaced data point for the increasingly conventional wisdom among independent political observers that Democrats are going to take back the majority in the House of Representatives this November. Even if Democrats only come close to winning, some are calling that a success.

Judging by their actions, Republicans seem to agree. Here are four signs that they are panicking about losing Ohio's 12th Congressional District on Tuesday with the full knowledge of how much this race matters to the broader fight for control of the House.

1. President Trump campaigned there Saturday: There is no better illustration that Republicans are pulling out all the stops to keep this seat.

Vice President Pence went there twice. House Speaker Paul D. Ryan (R-Wis.) made a visit. Trump interrupted his vacation at his golf course in New Jersey to go to Ohio. Departing Ohio Gov. John Kasich (R), who is a critic of Trump's, also endorsed Republican Troy Balderson in the final days of the campaign.

This was supposed to be a race with which Republicans wouldn't have much of a problem. Now they are throwing aside internal party fights to try to help Balderson get elected.

2. Polling shows a tight race: An independent poll out Wednesday, less than a week before the election, showed the race basically tied. Monmouth University has Balderson with a 1 percent lead, which is statistically insignificant, over Democrat Danny O'Connor, 44 percent to 43 percent.

A month ago, Balderson was ahead by 10 points in a Monmouth poll. This is just one poll, but such a dramatic shift in the last few weeks of the race should worry Republicans, since the final few weeks are when voters tend to start paying attention.

Dig deeper into the numbers and you find more bad news for Republicans. O’Connor supporters are 16 percentage points more likely to say they have a lot of interest in this election than Balderson’s.

It hints at a troubling trend for Republicans that has been lapping at their feet in other primaries and special elections this year: In the Trump era, Democrats seem more motivated than Republicans to vote.

Democrats have picked up more than 40 state legislative seats across the nation since Trump became president, some deep in Trump country. This spring they also flipped a congressional district in Pennsylvania — again, deep in Trump country. That narrowed the number of seats Democrats need to pick up in November to take back the House, trimming the target number from 24 to 23.

3. Each candidate is his party's top pick: After Republicans lost that congressional race in Pennsylvania, they whispered that the reason was the candidate-talent differential. They just didn't have a good candidate; Democrats had a great one.

As The Washington Post's David Weigel reports, making that claim is not an option in the Ohio race. Balderson and O'Connor are the candidates each side wanted.

“Nationally, the momentum is on the Democrats’ side,” Tiberi, the departing congressman, told Weigel. “You’re going to see a lot of money coming in to help O’Connor. The Democrats did a good job with him. They recruited a blank slate.”

Much as Rep. Conor Lamb (D) did in his victorious campaign in Pennsylvania, O'Connor has met this Republican-leaning district's voters where they are. He has run ads saying he won't support House Minority Leader Nancy Pelosi (D-Calif.) for speaker if Democrats control the chamber next year, a buzz issue among conservatives. He skirts abortion and avoids bashing Trump to talk about health care and the deficit.

So O'Connor is good but Balderson, a state senator, was a top recruit for Republicans, even if some think he is not doing as well as he should be.

4. This race is about as symbolic as a race can be: There is always a risk of extrapolating too much from one election. Republicans have argued that Democrats' recent success in special elections is unique to special elections. Democratic donors and activists across the country are focused on a single race, which is very different from the actual game day in November, when 435 House seats are up for election.

But in politics, symbolism sometimes matters as much as the result. This battle in Ohio will be the last competitive special election until November. It will leave a taste in everyone's mouth about what is possible in the midterms.

It is just one race, and Republicans might win it. But so much is on the line that they are not taking any risks.

Scott Clement contributed to this report