Voters are switching party affiliation in Pennsylvania at a rate not seen in years, if ever, as their chance to cast ballots in a competitive presidential primary election approaches.

The latest statistics this week from Pennsylvania's elections bureau show about 245,000 registered voters have switched this year, or 3 percent of the state's 8.2 million registered voters.

This is the first year voter registration in the state can be done online, making it easier than getting the paperwork, filling it out and submitting it. But many of those switching parties reported wanting to vote in Pennsylvania's April 26 primary, and the switching accelerated in the weeks before Monday's deadline to register to vote or change registration.

In Pennsylvania, closed primaries are open only to the party's registered voters and, historically, races tend to be settled by the time the state's relatively late primary election date arrives.

This year, contested primaries, particularly the closely contested Republican race, are driving up voter interest.

Among those making a switch, about half became Republicans, according to state statistics as of Monday. One-third became Democrats and the rest joined a minor party or registered as unaffiliated.

Complete state records on voter registration changes were not available Wednesday for comparison. But pollster and public affairs professor Terry Madonna of Franklin and Marshall College in Lancaster said he believes the rate of party switching is a modern record in Pennsylvania.

Still, Madonna said, it is hard to tell which presidential candidate the vote switching will benefit the most.

And the numbers do not signal whether voters are switching to vote for or against a certain presidential candidate in an election-year campaign that has brought out strong reactions for and against Republican front-runner Donald Trump. It has also spurred a surge in support for Democrat Bernie Sanders, although Hillary Clinton enters April with a big delegate lead and strong support among Democrats crucial to the nomination.

Some party switchers have been positioning themselves to help a candidate they supported, Madonna said.

"But as we've gotten close to the deadline, a lot of Democrats have changed to do what political scientists call 'strategic voting.'" Madonna said. That could include people voting for Trump because they think Clinton can beat him more easily, or voting against Trump out of dislike or fear, Madonna said.

The movement also could be helping one of Trump's GOP rivals, Ohio Gov. John Kasich, Madonna said.

Those who switched their registration and were interviewed by The Associated Press or other news organizations gave a variety of reasons for their decision.

Some like Jason Arnold, of Harrisburg, reported becoming a Democrat to vote for Sanders. "Bernie was the only one who was dealing with the income issue," said Arnold, who had been registered as a Libertarian.

Valerie Bonacci, of Scranton, switched her registration from Democrat to Republican to support Kasich, whom she views as the most experienced GOP candidate for the job, although if Kasich and Clinton win their party nominations, she will be torn over whom to support.

"I'm playing a strategic game," Bonacci said. "I think Hillary has (the Democratic primary election) pretty wrapped up here in Pennsylvania, so for my vote during the primary to have any kind of effect, it could be best used by voting for Kasich."

While most party switchers joined the Republican Party, the news wasn't all good for the GOP.

More unaffiliated or third-party voters joined the Democratic Party this year — 52,200 became a Democrat while 42,600 switched to the GOP — and Democrats signed up more new voters this year, 70,000 to 55,500, according to state data. Pennsylvania has supported the Democrat in every presidential election since 1988 and Democrats headed into the primary with a significant advantage, slightly above 4 million voters to nearly 3.1 million GOP voters.

The hottest area for party switching was in northeastern Pennsylvania — in particular, Carbon and Lackawanna counties — as a percentage of total registered voters, according to an Associated Press analysis.

Counties reporting the highest proportion of voter registration switching also led Pennsylvania with the highest percentages of voters becoming Republicans, according to AP's analysis.

Counties are still processing new voter registration records, and have until April 18 to submit final numbers to the state.