Congratulations on some fine acceptances! Carleton, in particular, is a school with a longstanding national reputation for academic excellence. In terms of campus politics and general vibe, Carleton and Grinnell (especially the latter) are known for their very liberal, “progressive” stances–both on the specific hot-button cultural issues of the day and, more importantly, on underlying questions of ideology or worldview. Wheaton seems to me to be the outlier here. It’s not so much that Wheaton is “conservative” as opposed to liberal; rather, it’s that Wheaton’s evangelical identity means that students and faculty alike are bound to approach contested issues from an ideological–or, better, theological–perspective that is quite incompatible with that which dominates at the vast majority of elite LACs and universities (including all of those on your list except for St. Olaf, which is in the more socially respectable, if fast-fading, tradition of “mainline” American Protestantism).
Of course, this disparity would register most obviously in fields like Religious Studies, Philosophy, and English–fields where considerations of “values” are central to the discipline. I’m not sure how much of an effect Wheaton’s Christian identity would have on the teaching of Political Science and/or IR. My guess is that it wouldn 't be much . . . though I doubt you’d have any neo-Marxist professors who analyzed American foreign policy in terms of “hegemony,” “empire,” etc.
From what I can tell, Wheaton is academically very strong. Its 75th-percentile SAT scores are in the range of top LACs like Colby and Bates. I suspect that if the college ditched its religious connection tomorrow (impossible as that would be), it would zoom up about 20 spots in next year’s USNWR rankings. Informed, open-minded people will be aware of this excellence; they won’t hold the “Christian” tag against you. However, Christianity in general is becoming rapidly marginalized in the US, and there are already rumblings afoot from esteemed academics who think that Christian colleges should lose there accreditation just as a matter of general principle.
In short, you will encounter people who are prejudiced against a Wheaton degree–and the number is likely to grow in the future. You need to consider such matters very carefully in making your college decision. If you want a prestigious degree and are willing to de-emphasize or bracket your Christian commitment for four years, go to Carleton. If you want a college education which takes up the challenge of integrating faith and reason (a challenge that defined the Western university from the time of Aquinas until the turn of the 20th century), then consider Wheaton . . . but know that choosing Wheaton would entail making a serious life commitment that might involve a degree of sacrifice on down the road. Such is not the case with your other options.
Note: St. Olaf might be a nice compromise. Its culture is not antithetical to Christianity, but it doesn 't have the scary “evangelical” moniker that drives secularists into a feeding frenzy.