logrolling

also log-rolling, in the legislative vote-trading sense, 1823, American English, from the notion of neighbors on the frontier helping one another with the heavy work of clearing land and building cabins (as in phrase you roll my log and I'll roll yours); see log (n.1) + rolling.

LOG-ROLLING. 1. In the lumber regions of Maine it is customary for men of different logging camps to appoint days for helping each other in rolling the logs to the river, after they are felled and trimmed -- this rolling being about the hardest work incident to the business. Thus the men of three or four camps will unite, say on Monday, to roll for camp No. 1, -- on Tuesday for camp No. 2, -- on Wednesday for camp No. 3, -- and so on, through the whole number of camps within convenient distance of each other. [Bartlett]

In politics, advance agreement by legislators to vote for one another's bills. Logrolling is most common when legislators are trying to secure votes for bills that will benefit their home districts. For example, a group of congressmen from the Middle West pushing for higher dairy prices and a group of southern congressmen supporting higher tobacco prices might make a logrolling agreement in order to get both bills passed.