Americans are losing faith in the value of a college degree, with majorities of young adults, men and rural residents saying college isn’t worth the cost, a new Wall Street Journal/NBC News survey shows.

The findings reflect an increase in public skepticism of higher education from just four years ago and highlight a growing divide in opinion falling along gender, educational, regional and partisan lines. They also carry political implications for universities, already under public pressure to rein in their costs and adjust curricula after decades of sharp tuition increases.

Overall, a slim plurality of Americans, 49%, believes earning a four-year degree will lead to a good job and higher lifetime earnings, compared with 47% who don’t, according to the poll of 1,200 people taken Aug. 5-9. That two-point margin narrowed from 13 points when the same question was asked four years earlier.

The shift was almost entirely due to growing skepticism among Americans without four-year degrees—those who never enrolled in college, who took only some classes or who earned a two-year degree. Four years ago, that group used to split almost evenly on the question of whether college was worth the cost. Now, skeptics outnumber believers by a double-digit margin.

Conversely, opinion among college graduates is almost identical to that of four years ago, with 63% saying college is worth the cost versus 31% who say it isn’t.