Something is happening in Pennsylvania.

As Twitchy reported yesterday,  a new poll has Mitt Romney 4 points ahead of President Barack Obama in the Keystone State.

But it’s not just Romney.  The Republican nominee for U.S. Senate, Tom Smith, is also making huge gains.

Less than two months ago, Smith was 19 points behind  the incumbent, Democrat Sen. Robert Casey Jr., and this race looked lost for Republicans. This week, however, two polls (see  here and here), show the race is within three points.

Robert Vickers of The Patriot News:

For months, Democratic U.S. Sen. Bob Casey Jr. enjoyed a commanding — even cavernous — lead over Republican challenger Tom Smith.

Those days are over.

Casey now holds a slim advantage in what had been considered one of the safest races in the country for Senate Democrats. With a huge blitz of TV ads, Smith has pulled himself into the race.

“This race is too close to call,” said Tim Malloy, assistant director of the Quinnipiac University Polling Institute.

The unemployment rate in Pennsylvania is higher than the national average and increased slightly in August (from 8.1 percent to 8.2 percent). Fracking and coal are big issues that play to Romney’s strengths (and Obama’s weaknesses).

According to Collin Hanna, writing in The Mercury, “Roman Catholics compose up to 36 percent of voter turnout [in Pennsylvania], one of the highest in the nation.” The Obama administration’s effort to mandate coverage of birth control plays well in Hollywood, but it doesn’t play so well here.

Moreover, Bob Casey’s campaign has been rather lackluster:

It looks like Pennsylvania Democrats are starting to get nervous, and rightly so: