The World-Herald has tended to endorse moderate conservatives in Iowa’s U.S. Senate contests. But this year, The World-Herald is voicing support for incumbent Sen. Tom Harkin as he seeks a fifth term.

This newspaper has great differences with the senator’s liberal take on economic policy and government activism in general. But this newspaper also regards it as fundamental that Midlanders need to elect U.S. senators with the necessary heft for the job.

In the 2008 Senate contest, Harkin demonstrates that gravitas. His conservative Republican opponent does not.

Harkin has shown commendable qualities in his Senate service, in particular as chairman of the Agriculture Committee. Harkin has earned great respect for dealing candidly with colleagues and outsiders; he is not a small-minded Capitol Hill manipulator.

Iowa’s senior senator has been impressively open to new ideas in farm policy, rather than sticking blindly to the expensive status quo as stubbornly demanded by so many cotton- and sugar-state lawmakers. Although Harkin has not always prevailed in those legislative battles, he has shown a commendable openness to moving beyond the same-old, same-old.

In his new farm bill passed this fall, Harkin did make sure that the measure included several positive elements. Increased incentives for conservation – long a focus for Harkin – were one success. So was the bill’s move toward shifting more farm payments toward forms that pass muster under international trade agreements—a legislative need that World-Herald editorials have highlighted over the years.

The Iowa senator did outstanding work this year in helping to bring together all the key players – from the disabled-advocacy community, business and government – to negotiate a workable follow-up to the Americans With Disabilities Act. That achievement, on an issue involving great complexity and differing interests, showed Harkin at his legislative best.

Iowa voters would do well to support Sen. Tom Harkin as he seeks reelection.