By Jim Melwert

NORRISTOWN, Pa. (CBS) — Republican Ryan Costello’s announcement that he will not seek re-election to his congressional seat in Pennsylvania’s sixth district is leaving the GOP  in a bit of quandary.

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The 41-year-old Pottstown native will retire at the end of his term but says the decision was not easy.

“Well it was a difficult decision. It was something that weighed on me for the past couple of weeks,” Costello tells CBS3.

The two-term congressman says his young family and political environment played roles in his decision.

“When I look at the state of our political environment, I lament how nasty and ugly it is right now and I don’t think that’s the kind of environment that I want for re-election” said Costello.

Costello also says, if and when he disagrees with the president, he also feels the wrath from pro-Trump Republicans.

Costello’s decision comes as no surprise. He’s been hinting at this for weeks, but the timing presents a challenge for party leaders, says Republican operative and lobbyist John Keleman.

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Rep. Ryan Costello Will Drop Bid For Reelection In Pennsylvania

The deadline to get on the ballot passed last week, the deadline to take a name off the ballot is Tuesday. That leaves the GOP with three options: Take Costello off the ballot and either accept Greg MacCauley as the Republican candidate or try to organize a write-in campaign; or keep Costello on the ballot through the primary, and, if he wins, party leaders could then hand-pick his replacement.

“In a primary election to ask voters to make what essentially would be a proxy vote for someone to be selected by party leaders, that’s a very tall ask,” Keleman said.

Keleman says for a new candidate to develop the name-recognition and goodwill that Costello’s developed in more than a decade in local and county politics, it would likely cost millions.

“And when you’re facing a candidate in Chrissy Houlahan, who already has a million dollars in the bank and has the full support of the DCCC, that is a very, very tall task,” he said.

“I’m honestly not very surprised that he decided not to run,” said Matthew Kerbel, Villanova University’s political science chair.

He says Costello’s move is having a positive impact for Democrats.

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“If you look at the totality in what’s happening across the country, Democrats feel very optimistic that in the fall they are going to be able to make inroads and possibly take back at least one house of Congress from Republicans,” said Kerbel.