But on Tuesday, Toomey rode into office on a wave of populist anger directed at President Barack Obama and some of his most costly programs, such as the stimulus package and the health care reform law.
Four years after ousting ardent social conservative Rick Santorum from office, Pennsylvanians cast their votes for a fiscal conservative whose ideas about the role of government has energized a base of supporters who have expressed fears about the growing deficit.
As head of the Washington-based Club for Growth, Toomey led the effort against moderate Republicans. In this race, Toomey's real prize was winning over enough independents, who may not have embraced his ideology in its entirety, but yearned for change and equated Sestak with Obama.
Toomey, not surprisingly, didn't fare so well with Jews. As a result, they had little if any impact on his win. Two separate Election Day surveys found that the majority of Jews supported Sestak, though their numbers differed somewhat.
One poll, sponsored by J Street, the dovish lobbying group, found that 71 percent of Jews backed Sestak, while 23 percent went for Toomey.
A separate poll, sponsored by the Republican Jewish Coalition, found that 62 percent of Jewish voters backed Sestak and 31 percent voted for Toomey. Both polls surveyed 600 Jewish voters in Pennsylvania by telephone on Election Day.
The J Street poll was conducted by Gerstein-Agne Strategic Communications, self-identified Democratic pollsters.
According to Jim Gerstein, the lead pollster, "Sestak would have won had there been more Jews in the population."
For its part, the RJC, whose survey was conducted by Republican pollster Arthur Finkelstein, said the number of Jewish voters for Toomey reflected a trend of Republican inroads with the Jewish community.
Even if they didn't love Sestak, Jews by and large found Toomey just too conservative to back, according to interviews with local voters.
From the outset, the anti-abortion, anti-gay-marriage candidate faced a tough challenge in the Jewish community, which tends to vote overwhelmingly Democratic, although he stressed that his campaign was about economic, and not social, issues.
But he was in stark contrast to the moderate Sen. Arlen Specter, the Republican-turned-Democrat he's now replacing. In fact, some established GOP Jewish fundraisers did little or nothing on Toomey's behalf.
Though few in number, some were drawn to Toomey's philosophy of fiscal discipline.
Reached after midnight on Election Day, Michael Adler, who chaired Toomey's campaign in Lower Merion, sounded ecstatic, if a little tired.
"He's not the far-right extremist that the left likes to paint him as," said the 37-year-old. "He's a fiscal conservative, which is what the state needs right now."
In contrast, Sestak supporter Mel Shralow, 74, shuddered as he watched returns come in at the candidate's Election Night party at the Radnor Hotel.
"The Jewish community will suffer in the same way that the American community will suffer," he said, adding that the GOP would try to overturn President Barack Obama's agenda.
But David Broida, who helped organize pro-Sestak ads in the Jewish Exponent and the Pittsburgh Jewish Chronicle, said the results don't signify the end of the world. Toomey, he said, will have just one vote out of 100. Now, he said, it's time to start thinking about the 2012 election.
All told, Toomey spent less time addressing Jewish audiences than his Democratic opponent. One Jewish supporter, Robert Guzzardi, said that he suspected that the campaign felt it had little to gain by investing heavy resources and time in the Jewish community.
Late in 2009, before concerns had been allayed somewhat in certain segments of the Jewish community over Obama's approach to the Mideast, Toomey seemed determined to portray himself as the most ardently pro-Israel candidate.
But as the general election kicked into high gear at the end of May, Toomey was determined to zero in with laser-like focus on the economy, and was content to let groups like the Republican Jewish Coalition attempt to cast doubt on Sestak's pro-Israel bona fides.
But Sestak — and especially, his Jewish supporters — attempted to turn the tables and point out that, during his six years in the House, Toomey had cast numerous votes against foreign-aid appropriations, which includes an annual sum of roughly $3 billion to Israel.
Toomey has said he's opposed to parts of the foreign-aid bill, but not to offering military assistance to Israel as part of a different package.
Like U.S. Rep. Eric Cantor (R-Va.), the lone Jewish Republican in the House who will now most likely become the next House majority leader, Toomey has proposed creating a separate bill solely for Israel aid.
Toomey has made a pledge to avoid earmarks, which lawmakers bring back home. But Jewish groups have long supported them, and locally, Federation has used earmarked dollars to boost its aging-in-place initiative.
Robin Schatz, director of government affairs at the Jewish Federation of Greater Philadelphia, has met with Toomey and pressed him to rethink his stance on earmarks. Schatz said she told him in the spring that he shouldn't think of earmarks as a four-letter word.
"I think there are some fundamental differences between Toomey and the Jewish community," Schatz said the day after the election. In the same way we were able to find common ground with Rick Santorum, she added, "we will be able to find common ground with Senator-elect Toomey."