This list is at a variety of price points, with club rowing or intercollegiate (but not D1 or offering rowing scholarships), with an enrollment under 6,000 (unless noted otherwise) and international relations (or similar) and political science majors offered.
Extremely Likely (90+%)
- Wheaton
- College of New Jersey (slightly larger than your limit at 7,000 undergrads)
- DePauw
- Marist
- St. Lawrence
- Butler
- SUNY Geneseo
- Hobart & William Smith
- St. John Fisher
- Endicott
- Ithaca
- Le Moyne
- Susquehanna
- Gordon
- Hampden-Sydney (all men)
Likely (60-90%)
- Skidmore
- Franklin & Marshall
- Connecticut College
Possible (25-55%)
- Bucknell
- College of the Holy Cross
- Kenyon
- Lehigh
- William & Mary
- U. of Richmond
- Lafayette
Unlikely (less than 25%)
- Williams
- Washington & Lee
- Vassar
I think your son is likely to get very significant merit aid at a number of these universities. And although your son has great stats, colleges is the unlikely bucket are unlikely for all applicants, simply because of the very large numbers of highly-qualified students who apply.