Did you know Sen. Ben Cardin (D-Md.) is a great guy? He’s got “compassion” and “brains” and he’s a “tremendous leader.”

That’s the takeaway from a pair of e-mails that arrived in the inboxes of many Democrats Tuesday morning — one from Gov. Martin O’Malley (D) and one from Cardin’s wife, Myrna — urging recipients to open up their wallets for the Maryland senator’s reelection bid.

“Ben keeps his promises and never shies away from what he believes in. And he’s got the brains and good sense needed to get the job done,” Myrna wrote in an e-mail from Cardin’s campaign, later adding: “We need Ben to remain in the Senate to keep up the fight, but the only way he can do it is with your help. “

O’Malley, meanwhile, sent a message to his own campaign supporters saying: “When I first ran for governor, Ben Cardin was there to help us move Maryland forward. Now it’s time for us to step up for Ben, and I couldn’t be more proud to do so.”

Why all the praise for Cardin today?

Because the 2nd quarter of the year ends Thursday night, so campaigns of all kinds are busy trying to solicit last-minute donations for their fundraising reports that are due July 15. Though Election Day is still more than 16 months away, putting up good early numbers serves a useful purpose for an incumbent in Cardin’s position by helping him scare off potential Republican challengers.

So far the best-known Republican to jump into the race against Cardin is Daniel Bongino, a political novice who has drawn media attention because he quit his job as a Secret Service agent to enter the contest. Bongino has been making the rounds of Republican events and media interviews, but it’s not yet clear whether he will be able to raise the millions of dollars necessary to run a competitive statewide campaign.

Former Queen Anne’s County Commissioner Eric Wargotz (R), who lost to Sen. Barbara Mikulski (D) in 2010 by 26 points, is also considering a run against Cardin and plans to make a firm decision later this year. He has the ability to support his own campaign financially — he put more than $600,000 of personal money into his 2010 bid — but his performance last cycle wasn’t necessarily so strong that it would scare off other GOP contenders.

Cardin, for his part, raised $756,000 in the first quarter of the year and had $1 million in the bank as of March 31.