P.G. Sittenfeld’s fundraising has slowed dramatically in the second quarter — a sign that former Ohio Gov. Ted Strickland’s entry into the 2016 race for the U.S. Senate has quashed some of Sittenfeld’s early momentum.

Sittenfeld, a Democrat, last quarter raised $272,136, his campaign announced Friday — far less than the $750,000 he brought in during the first few months of the campaign.

Strickland, Sittenfeld’s primary opponent, meanwhile, brought in a little more than $1 million last quarter and has $1.2 million on hand. Sittenfeld has $725,000 in the bank and has raised a little more than $1 million to date.

The two Democrats are vying to oppose Sen. Rob Portman, R-Ohio, whose campaign announced earlier this week has $10 million in the bank and who raised $2.9 million last quarter.

The Ohio Democratic Party and national Democrats moved quickly to rally around Strickland after he entered the race earlier this year, endorsing him and denying Sittenfeld a speaking slot at the most recent Ohio Democratic Party dinner.

Strickland — a longtime congressman and a former one-term governor — has led Portman in at least one poll, but analysts say that his fundraising is far short of what is needed to compete effectively with Portman. Portman, meanwhile, leads Sittenfeld in those same polls.

Sittenfeld’s campaign received more than 900 donations in the second quarter, and 80 percent were for $250 or less.

Sittenfeld spokesman Dale Butland said Sittenfeld is still introducing himself to voters around the state. “Message trumps money and P.G.’s got a better message than either of his opponents,” Butland said.

Campaign finance reports are due to the Federal Election Committee July 15. Those reports will offer more specifics on who has given to both campaigns and what the campaigns have spent their money on.