Rep. Steny H. Hoyer is one of the most powerful Democrats on Capitol Hill, but he might not be so popular back home.

The Maryland Republican Party announced last week that, thanks to a voter-registration drive this year, Mr. Hoyer’s home county of St. Mary’s County now has more Republicans than Democrats.

The state GOP issued a news release last week celebrating the shift, which now shows the county to have 24,448 registered Republicans and 24,340 registered Democrats — a difference of just 108 people. Going into 2012, St. Mary’s Democrats edged their GOP counterparts by 158 registered voters.

So what does that mean? It depends who you ask.

Mr. Hoyer, the House minority whip who has been in office since 1981, is still a heavy favorite for re-election against Maryland Delegate Anthony J. O'Donnell. His home county may be ever-so-slightly red but his district includes large swaths of heavily Democratic Charles and Prince George’s counties.

The GOP probably won’t be taking Mr. Hoyer’s seat anytime soon, but state Republicans were quick to run with the good news and pile on the longtime congressman — declaring him out of touch and the target of a revolt by neighbors who were fed up with his landslide victories and liberal politics.