Thousands of Kentuckians have switched political parties over the past three months, apparently in hopes of voting in the Democratic presidential primary.

Problem is Secretary of State Trey Grayson says Kentucky law forbids people who switch parties after Dec. 31 from voting in the presidential primary.

Grayson said Kentucky election officials have been warning political groups and campaign workers that encouraging Republicans and independents to switch to the Democratic Party will be of no benefit in the primary.

Some 9,000 people have switched parties since Jan. 1.