A millionaire real estate developer is poised to enter the Democratic Senate primary in Maryland next year.

The question is whether Joshua Rales is fated to run a costly, ego-driven campaign that struggles to gain traction or whether he can change the dynamic of the Democratic race — and maybe even win.

The latter seems like a tall order. Rep. Benjamin Cardin (D) is already the favorite of much of the party establishment, and former Rep. Kweisi Mfume (D) is almost guaranteed a decent chunk of the primary vote. Rep. Chris Van Hollen (D) is exploring the race, and other elected officials are also taking a look.

Rales may not even be the only self-funding political novice in the race: forensic psychiatrist Lise Van Susteren is seriously considering entering the Democratic contest and is seeking counsel from a team of consultants that includes media strategist Tad Devine and pollster Diane Feldman.

If Van Susteren is the only woman in the Democratic field — Anne Arundel County Executive Janet Owens is also contemplating the race — she could prove to be formidable.

Rales has also reached out to an array of senior Democratic strategists — though he hasn’t hired anyone to work for him yet. But in contrast to Van Susteren, who is the sister of Fox News personality Greta Van Susteren, Rales is giving media interviews and making the rounds of Maryland political events.

“He talks to everybody,” said one Washington, D.C.-based consultant who has conferred with Rales.

Rales said he is becoming increasingly convinced that voters are looking for a candidate who isn’t a “professional politician,” and argued that he alone has ideas for keeping the United States competitive in the 21st century economy.

“I think there’s an opportunity for a straight-shooting problem-solver,” the 47-year-old said. “A lot of these professional politicians don’t understand the real world.”

The one problem he may not be able to solve is one of his own making: He is a two-time party switcher.

Just two years ago, Maryland Republican leaders were wooing Rales to challenge Sen. Barbara Mikulski (D) in 2004. He declined, determining that the task was impossible.

Last August, Rales — who after a lifetime as a Democrat joined the GOP in the mid-1990s because he liked the fiscal conservatism and the accountability measures laid out in the “Contract with America” — switched again and became a Democrat. In the past decade, he said, it is the Republicans who have become fiscally irresponsible.

Rales is unapologetic about his recent return to the Democratic Party and said that if the Democrats are serious about expanding their base, they will need to reach out to political moderates like him.

“Some people are going to criticize” the conversion, he conceded. “I tell them that if Democrats are going to get back in the majority, they need more people.”

Still, Democratic voters will not like the roster of Republican candidates Rales has contributed to in recent years. According to Political Money Line, he gave at least $23,000 to federal GOP candidates and committees in the 2002 and 2004 cycles — not just to moderate Republicans like then-Rep. Connie Morella (Md.), but to President Bush, then-Sen. Bob Smith (N.H.), now-Sen. John Thune (S.D.), and Chuck Floyd, Van Hollen’s challenger last year.

Rales did give $3,000 to House Minority Leader Steny Hoyer (D-Md.) in the 2004 cycle — but he was an intern in Hoyer’s office during college.

Rales said one of the things that will determine whether he ultimately gets in is whether he can assemble a quality team to guide his campaign. One of the people Rales has reached out to is Steve Jarding, who helped elect another Washington, D.C.-area businessman, Mark Warner, as governor of Virginia in 2001. Warner by then had already run a high-profile statewide race (a closer- than-expected run for Senate in 1996) and had a long history as a Democratic activist and donor.

Even if Rales hires top-flight staffers and consultants — and even if he antes up $5 million of his own money, as he has told some of the people he has spoken to about the race — many Maryland political professionals remain skeptical.

“It’s just another moneybags vanity candidate who gets 9 percent of the vote,” said one veteran of several statewide campaigns.

But another national consultant who has talked to Rales said the businessman is realistic about his chances if he runs.

“He knows it’s a long-shot bid,” the consultant said. “He knows it’s high risk. But he also knows he can’t win if he’s not in the game.”

If he gets in, Rales’ presence in the primary could alter the political dynamic — even in subtle ways.

Although he has no political base to speak of, he lives in Potomac, in Van Hollen’s district. Any siphoning off of voters in Montgomery County, Van Hollen’s turf, could come straight out of the sophomore Congressman’s total.

Van Hollen said he did not know how to assess Rales’ potential.

“Is he running?” he said. “All I know about him is he has a lot of money.”

At the same time, Rales is active in Jewish philanthropy, and his presence in the primary could depress the strong vote — and heavy donations — that Cardin is anticipating from Jews.

Equally significant, conventional wisdom suggests that a greater number of white candidates in the race improves Mfume’s prospects. While Mfume as the nominee could maximize black turnout in the general election, some Democrats fear that he has been irreparably damaged by news articles detailing charges of favoritism during his tenure as president of the NAACP.

With Mfume’s political strength unclear in the wake of the allegations, one top Democratic operative in Maryland has even half-jokingly suggested that Rales has been put up to running by the state Republican leaders who once wanted him on their ticket, to ensure that a potentially weak nominee — Mfume — emerges for the general election with the likely GOP choice, Lt. Gov. Michael Steele.

Rales laughed at the suggestion.

“Why would I do that and make the investment I’d be making?” he said.