By JULIE PACE, AP White House Correspondent

CLINTON, Iowa (AP) — Hillary Clinton's most loyal and enthusiastic supporters in Iowa — women middle-aged or older — are unwavering in their support of the Democratic presidential candidate.

But some are grappling with a combination of confusion and anxiety that another race in Iowa could be slipping away, just like in 2008.

This time around, the unexpected challenge to Clinton comes from Vermont Sen. Bernie Sanders, the self-described democratic socialist who has energized young voters and liberals with his calls for a "political revolution." Days before next Monday's caucuses, Sanders' crowds are routinely doubling or tripling Clinton's, particularly in college towns.