Twenty-three is still the magic number. That's how many seats the Democrats need to flip in order to take control of the House of Representatives in January.

History is certainly on their side. Through the past century and a half, the party that held the White House has typically lost more than 30 seats in the first mid-term election. That's obviously enough to get the Democrats into the majority in and of itself.

But history doesn't determine elections, voters do.

What's November 2018 going to bring? As with many recent elections, the national answer lies in the Keystone State.

Pennsylvania has a huge registration advantage for Democrats, but Republicans have still managed to win statewide elections, including Donald Trump's and Pat Toomey's victories in 2016, and to control both chambers of the General Assembly. At the beginning of the session, they held a 13-5 advantage in the state's congressional delegation.

The Pennsylvania Supreme Court changed the equation significantly with its "judicial-mandering" of the state's congressional lines earlier this year.

Adding to a massive shakeup of the state's congressional delegation was an unusually large number of retirements and resignations. Open seats are more hotly contested than ones where incumbents are running.

With the road to 23 running right through Pennsylvania, Democrats see the opportunity as a major step in their direction.

They're likely to pick up some seats here. Most specifically, two seats in the collar counties around Philadelphia look especially vulnerable. One is the 5th District vacated by Rep. Pat Meehan. The other is the 6th District, where the untimely announcement by Rep. Ryan Costello of his retirement caught the GOP flat footed.

Democrats also thought they could pick up another Philly suburb seat in the new 1st District, held by freshman Rep. Brian Fitzpatrick. But their nominee is far to the left and has not proven to be an effective candidate. Fitzpatrick will hold his seat.

There are other Pennsylvania seats that may likely determine who controls Congress in the next session. At opposite sides of the state are the 7th District, vacated by Rep. Charlie Dent, and the 17th District, which pits two incumbents, Rep. Keith Rothfus and Rep. Conor Lamb, against each other.

The Lehigh Valley seat would have been an easier pickup for Democrats had they nominated moderate Northampton County District Attorney John Morganelli in their primary. Their nominee, Susan Wild, is on the far left of the Democratic Party and much more of a target.

On the other side of the state, Connor Lamb's star power, left over from the avalanche of national media he received in a special election in a different district earlier this year, gives him a leg up.

Keith Rothfus has been a solid, reliable and hard-working member of Congress. But he faces a tough battle to overcome the celebrity of the newly minted congressman.

Democrats' ambitions don't stop there. They think they've got a shot at Rep. Mike Kelly in northwest Pennsylvania. That's a stretch.

So is their insistence that they can take away the seat of Rep. Scott Perry here in the mid-state.

Perry faces a very different electorate than he did in his previously configured district. And he's got the first real fight of his congressional career. His margin of victory won't be anywhere near as big as he's used to. But you know what they call a guy who wins by a slim margin?

Congressman.

Presidential popularity always looms large in midterm elections.

President Trump's numbers are not where he'd like them to be, but they are not in the danger zone, either. His approval rating on the economy is above 50 percent, and the national mood, with unemployment way down, the economy up and no major international crisis to speak of, is in his favor.

There's not likely to be the "Blue Wave" Democrats are hoping for. It's more likely that the outcome will turn on a few tightly contested battles in individual districts.

There, enthusiasm and voter intensity will likely determine who wins. Democrats have boasted an "enthusiasm gap" for most of the year. That's closing. The "Silent Majority" lets its voice be heard later.

The Kavanaugh hearings undoubtedly increased voter enthusiasm and intensity for both the Democratic and Republican bases. How they affected the small number of undecided and still persuadable independent "swing voters" remains to be seen.

With just a couple of days remaining for voters to register, every eligible citizen should make sure that they're registered. With just over a month left to Election Day, every voter should have Nov. 6 circled on their calendar.

It's going to be a red-letter day, especially here in purple Pennsylvania.

 

PennLive Opinion contributor Charlie Gerow is the CEO of Quantum Communications in Harrisburg. His "Donkeys & Elephants" column appears weekly opposite progressive commentator Kirstin Snow.

Read on PennLive