By Edith Honan
NEW YORK, April 24 (Reuters) - Five Pennsylvania Republicans face off on Tuesday for the chance to run against Democratic Senator Robert Casey in November, while two incumbent U.S. Representatives, both Democrats, are competing for the state's newly combined congressional seat.
Pennsylvania voters on Tuesday will also cast votes in the Republican presidential primary, though that contest carries less suspense. Former Massachusetts Governor Mitt Romney appears almost certain to win since former Pennsylvania Senator Rick Santorum suspended his campaign earlier this month.
Several statewide races, however, are competitive.
The Senate primary pits Steve Welch, an entrepreneur who is backed by the state party and Republican Governor Tom Corbett, against Tom Smith, a former coal-mine worker who went on to own a coal company and has poured his own money into the campaign.
Former state Representative Sam Rohrer, who ran successfully against Corbett two years ago and is popular among Tea Party voters, attorney Marc Scaringi and Dave Christian, a Vietnam War representative, are also seeking the Republican nomination.
"There's three things at play: Smith's money versus Welch's endorsement versus the grassroots activism for Rohrer," said Terry Madonna, the director of the Franklin and Marshall College Poll.
While each of the candidates have fought for the banner of the race's true conservative, both Welch and Smith have sought to explain away an inconvenient line in both of their resumes - both used to be Democrats.
That fact has turned the Senate race into "the most bizarre Republican statewide primary I've seen in thirty years," said Madonna. "It's a Republican primary about who's the least Democratic."
The Republican victor will take on Casey, who was swept into office in an 18-point landslide six years ago, temporarily derailing the political career of then-Senator Santorum.
On the Democratic side, the race between fellow U.S. Representatives Jason Altmire and Mark Critz for a Pittsburgh area congressional seat was described by one state political reporter as a "fratricidal showdown."
Pennsylvania was due to lose one congressional seat as a result of the once-per-decade redistricting process, and the Republican-controlled state legislature combined the seats represented by the two Democrats, creating a new 12th District.
While Altmire was initially favored to win the race because his former constituents formed a majority of the new district, Critz has won important union endorsements and the backing of former President Bill Clinton, helping to close the gap.
In one of the more unusual Pennsylvania races, state Representative Bill DeWeese, a longtime Democratic leader, is running unopposed for re-election on the same day he is scheduled to be sentenced in Harrisburg in a corruption case.
In February, a jury found DeWeese guilty of theft, conspiracy and conflict of interest after prosecutors accused him of improperly using state resources to assist his campaigns.
Meanwhile, Republicans Mark Fischer and George Toothman are running for the chance to defeat DeWeese in the general election.
It is possible that DeWeese will campaign for the general election from a prison cell, or that he will step down or be removed from contention by the state party by Aug. 13 - the state deadline for taking a candidate off the ballot and announcing a special election. (Reporting by Edith Honan; Editing by Jackie Frank)