undercurrent

「底意、内心、底流」。

The New York Timesの本日記事、'Immigration Could Sway Coming Vote in Britain' by JOHN F. BURNSから。

'LUTON, England — When Mohammed Qurban stood outside the Jamia mosque in the heavily Muslim Bury Park district on Tuesday and spoke anxiously about Britain’s record-high levels of immigration, he was reflecting a powerful undercurrent that could help tip victory in dozens of constituencies in Thursday’s general election to the main opposition groups vying with the governing Labour Party for power, the Conservatives and the Liberal Democrats'.

ちなみに、例文中のvying withで、「〜と競う、張り合う」。発音は［va'iiŋ］。動詞vieは、こちらから音声が聞けます。