CNBC's John Harwood: White fear of change to blame for Democratic casualties under Obama
US President Barack Obama is the keynote speaker at the Democratic National Convention in Philadelphia (AFP Photo/Yuri Gripas)

CNBC host John Harwood said Tuesday that the Democratic Party's plight was due in part to white Americans who feared cultural change.

In a series of tweets, the veteran reporter said economic woes, opposition to the Affordable Care Act and Obama's race had all contributed to Democratic losses in recent years.

The Democrats have 63 fewer House seats, 10 fewer Senate seats and 12 fewer governorships since Obama became president.