For Mary Toomey, vice chairwoman of the York County Democratic Party, the primary-day rush had already begun by Thursday afternoon.
She said she had spent much of the day on the phone, trying to marshal a small army of poll-watchers to keep an eye on the 159 voting locations throughout York County. She said the effort involves hundreds of people.
Both her party and the Republicans will have poll watchers on hand to make sure everyone from their respective parties votes only once. They also have to keep an eye out for any hanky-panky, such as the people handing out flyers for candidates outside the polling stations wandering within a 10-foot perimeter of the voting machines, which is a violation of state election law.
Poll watchers are part of every election. But on Tuesday, things will be different for local Democratic Party leaders such as Toomey.
For one thing, spring primaries are usually a relatively low-key affair, compared with the November general elections. This year, county election officials are expecting a big turnout. For another, the most intense campaigning will almost certainly be between two factions of the Democratic Party - supporters of Hillary Clinton and supporters of Barack Obama.
"This has been a most unusual election," Toomey said.
County elections director Nikki Suchanic said she expects a bigger turnout on Tuesday than for any primary in recent memory. Still, she doubts the turnout will be as large as it typically is for November presidential elections.
She's betting that Pennsylvania's closed system, which allows only members of a given party to vote in that party's primary, will keep the numbers relatively low compared to a general election.
For her purposes, the election has the same logistical requirements as always. Each polling place must have a minimum of three people. That usually amounts to three people with elected positions: a judge of elections and two inspectors. Some large polling places might have a machine inspector.
Toomey said the poll watchers are there in addition to the three elected officials. A big part of their job is checking the list of registered Democratic voters in that district as the day wanes.
Somebody will call all of the registered voters who haven't yet showed up at the polls, Toomey said. They will make sure that those absent voters are able to get to the polls if they want to, even offering a ride if they have a problem with transportation.
Throughout the day, volunteers will be at Democratic headquarters to answer questions about polling places. In addition, local Democrats will have a lawyer around all day, to be ready should a legal question arise anywhere in the county.
Yet for all their involvement, the official representatives of the York County Democratic Party will remain nonpartisan, in accordance with primary precedent and their own bylaws.
Toomey said the poll watchers are instructed not to wear any buttons, T-shirts or other items that espouse a partisan view. They're also told not to engage in political discussions. That latter instruction can be particularly difficult to get through to poll workers, she said.
They tend to be there in the first place because they're interested in politics, and it's kind of like asking sports fans not to discuss football on the day of the Super Bowl. Nevertheless, political discussions are off limits, Toomey said.
For Democrats who aren't representing the local party in any official capacity, however, last minute campaigning on Tuesday is fair game. In fact, both the Clinton and Obama campaigns are planning on quite a lot of it.
Debbie Mesloh, an Obama campaign spokeswoman, said that hundreds of volunteers will be out to canvass, make phone calls and leave literature on doors. They're even counting on a few Obama volunteers to come up from Maryland, although Mesloh said that most of the people campaigning locally will be locals themselves.
"It's really a last-minute push to talk to people about why Obama is the best candidate for the Democratic Party and for the country," Mesloh said.
Clinton volunteers are poised for a similar last-minute push. Colleen Burkett of York Township, for example, said that she will be on standby all day. She'll have her cell phone at the ready, should a request come through for her to work the phones, hand out flyers outside the polling places or go door-to-door in a local neighborhood.
"Where they need me is where I'll be," Burkett said.
WHERE TO VOTE
--- In Pennsylvania, polls are open from 7 a.m. to 8 p.m.
--- To find out where your local polling place is, go to www.york county.org/voters/election.htm, or call 771-9604.
--- York County Democratic Party headquarters: 812-1200
--- York County Republican headquarters: 854-7276