Fair and free elections are at the heart of any democracy. But how fair is an election when voters aren't offered a choice at the ballot box?

That's the dilemma facing Maryland voters this year. After Tuesday's candidate filing deadline, 10 state senators appear destined to run unopposed in both the primary and general elections this year. Collectively, they represent more than one-fifth of the state.

That's actually better than four years ago, when 15 candidates for state Senate ran unopposed. That left nearly one-third of voters without a choice about who would represent them in that chamber of the General Assembly.

Even more surprising is the news that Attorney General Douglas F. Gansler drew no opposition despite his controversial — albeit correct in our view — position in support of same-sex marriages. Such unions have attained legal stature within Maryland thanks to his leadership. But it motivated no one to pay the modest filing fee and run against him?

The lopsided nature of Maryland politics is well-known. Democrats outnumber Republicans in this state by a greater than 2 to 1 margin and that advantage has only increased over the past four years. At the state party level, the GOP has suffered much financial and leadership travail — although the presence of a former governor, Robert L. Ehrlich Jr., at the top of the ticket was supposed to offset that.

And that's only part of the problem. There are Republicans, most notably state Sen. Barry Glassman of Harford County, running without challengers, too. Nor does it explain the lack of sufficient competition at the primary level. (Of those elected officials who do face opposition, many are up against unknowns with little organization or financial backing).

Most telling is the lack of an opponent for Ulysses Currie, the powerful Prince George's County state senator under federal investigation for allegedly using his influence on behalf of a grocery store chain that employed him, a relationship the senator failed to disclose. Even the taint of possible scandal failed to produce a challenge.

So why, with ongoing economic woes, a competitive race for governor, a boatload of volatile issues to debate from taxes to job losses and a supposedly outraged tea-partying national electorate, is there a shortage of candidates?

There are any number of possible explanations. But surely at the heart of the problem is the difficulty that any challenger faces in finding sufficient resources to take on an incumbent. Running for office requires time and money, quantities in short supply for average Marylanders.

Recently, Mr. Ehrlich was quoted in this newspaper complaining about the lack of business people in the legislature. Well, unless you're a lawyer or government employee, chances are your profession isn't well represented in the House or Senate either. Running for the state legislature can cost tens of thousands of dollars and take months, if not years, of effort. Holding the post requires leaving aside one's job for 90 days at minimum and usually much longer.

That last requirement probably can't be helped, but lawmakers could certainly make it easier for candidates to file for office by endorsing public financing of elections. Legislation to do just that (at least on a limited basis) died in the Senate this year.

Lawmakers ought to be embarrassed by the failure of campaign finance reform. Just as capitalism requires a reasonable opportunity for competitors to enter the marketplace, democracy needs to ease the entry for legitimate candidates for public office. Without competition, there is no free market of ideas, only the preservation — and inevitable stagnation — of the status quo.