Richard J. Durbin, the Democrat who beat Rep. Paul Findley, a Republican who had represented his central Illinois district for 22 years, had a lot going for him in the election.

The 20th District was 35 percent new and slightly Democratic. The economy there was in bad shape, with unemployment in some areas close to 20 percent. And Durbin, unlike many challengers, had money, more than $500,000, most of it contributed by Jewish groups incensed by Findley's controversial stand on the Palestine Liberation Organization.

In addition, Durbin was considered an exceptionally able candidate, a fact conceded by Findley supporters. A Springfield attorney, Durbin, 37, had worked for Illinois Sen. Paul Douglas and Rep. Paul Simon, and for more than 10 years served as parliamentarian of the state senate where he made many friends among the state's Democratic establishment.

He had run twice for public office and lost both times, in 1976 for a state senate seat that had been held by the GOP since 1906 and in 1978 for lieutenant governor on a ticket that was trounced by Gov. James Thompson.

Unlike Findley's opponent in 1980, Durbin did not make an issue of the PLO during the campaign. Instead, he concentrated on the economy, making a strong appeal to blue-collar strongholds in Decatur and other industrial centers. At an AFL-CIO rally in Decatur for the Democratic slate, Durbin got the strongest applause and proved himself one of the most forceful speakers. "We are going to change the course, because Reagan has flunked the course," he said to rousing cheers.

Durbin campaigned for a repeal of the third-year tax cut and a slowdown in the increase in military spending. "Too much, too fast," was the way he characterized Reagan's proposals for the military.

His economic proposals for central Illinois got less attention, although they plugged Democratic themes of "high-tech" development, more sophisticated education programs and repairs to the crumbling infrastructure.

He also advocated taking a tougher line against foreign countries that protect their industries from American imports, and on agriculture, campaigned for a return to a paid crop diversion program.