Why yes, it is difficult
In the comments to a post at Pharyngula, someone asked, " Okay... but is it really just as hard to get a job at a liberal arts college than at a research university?"
No job applicant in his or her reasonably right mind will apply to just one type of position; search pools at wildly different institutions will still share a large number of candidates. Some of our searches have pulled in over 300 applicants! One may be the proud possessor of a doctorate in English from Yale, but that doctorate will not necessarily prove helpful when it comes to obtaining a tenure-track job. Ivy League Ph.D.s now regularly wind up at both public and private liberal arts colleges, often with teaching loads rather higher than one might like to contemplate.
As a result, we now have more research-oriented faculty at teaching-oriented institutions. Granted, it may be necessary to pursue different kinds of research projects, as Chad Orzel notes, but still, many younger faculty can find something liberating in the more relaxed publishing requirements of a liberal arts college. Unfortunately, it's hard to dispel the belief that faculty at teaching campuses are somehow "also-rans," even when those faculty outpublish their brothers and sisters at Research I and IIs!
At the same time, it's true that Ph.D.s from private research institutions who apply to teaching campuses often have one mark against them: little or no teaching experience. Moreover, some of these Ph.D.s have not been trained to think in terms of life without TAs, let alone life with freshman composition. (My first job search was a botch for precisely this reason: the sum total of my experience consisted of two once-a-week discussion sections.) ) At a campus like mine, say, you cannot flub the teaching segment of your interview. You simply cannot. It may be necessary to offer informed hypotheses instead of answers from experience, but any way you slice and dice it, a flat "I don't know" will never be the right answer to a teaching question. Similarly, even if the college has an MA program, it's not a good idea to ask questions only about the graduate students; the undergraduates are everyone's primary responsibility. And don't even think about writing a cover letter in which you expend large quantities of ink on some esoteric theoretical issue, only to casually toss off a paragraph about teaching at the end!!