Bera is the only Indian-American in the current Congress and third ever person from the community to be elected to the US House of Representatives. He was elected from California's seventh Congressional district with a thin margin in the 2012 general elections.
49-year-old Bera is facing a tough competition from Republican Doug Ose, a businessman who served three terms in Congress through 2005.
"Hi, this is Michelle Obama, and I'm calling because Barack and I are counting on you to support Ami Bera and the Democratic ticket this November 4," the First Lady said in the recorded phone message.
"In an election this close, your vote is more important than ever before. We can't risk having more out of touch folks coming to Congress, just because a handful of Democratic voters stayed home," she said.
"You've been one of our reliable supporters in the past, and I hope you will make your voice heard again this year. Thanks so much," Michelle said in the phone recording which was released yesterday.