After a heated primary to choose a challenger for President Obama, Republicans are fast becoming bored with the 2012 campaign, according to new data from the Pew Research Center.

Six in 10 Republicans say the presidential campaign is “dull” — up 18 percentage points from March and surpassing Democrats for the first time this cycle. By contrast, Democrats are becoming more interested as the general election campaign unfolds, with just as many now saying the race is “interesting” as say it’s dull. Independents continue to be the least engaged with nearly two-thirds calling the race dull. 

Republicans' newfound listlessness stands in contrast to their increasingly positive views of their nominee. The percent of Republicans with a favorable impression of former Massachusetts governor Mitt Romney grew from 62 percent in late March to 78 percent in early June, according to Washington Post-ABC News polls.

But liking is not loving, and a May Post-ABC poll found more than twice as many Obama supporters said they were “very enthusiastic” about their candidate than Romney supporters.

Since the Republican primary ended in April, Democrats have enjoyed an enthusiasm advantage. Democrats were 13 points more likely than Republicans to be “extremely” or “very” enthusiastic in a July CNN poll. That compares to the rough parity between Republican and Democratic voters in March.

Republicans’ “dull” assessment the current campaign may reflect the slower pace of the current campaign compared with the day in, day out excitement of the primary. The latest Pew numbers may fade away with party convention season. In 2004, for instance, 57 percent thought the campaign was dull in June, but that dropped to 42 percent in September (and just 28 percent in October).