Legislative races used to be low-budget affairs decided on local issues, if they were decided on issues at all.

The candidate who worked the hardest, knocked on the most doors, marched in the most parades and shook the most hands usually won. Since the passage of the Clean Election Act, first used in the 2000 election, most candidates from both parties found that they could qualify for all the money they needed and could focus on meeting voters.

All that has changed since a series of Supreme Court decisions that opened the door to unlimited and anonymous spending outside the confines of a formal campaign, and outlawed the matching funds Clean Election candidates could expect if they were outspent by an opponent.

In 2010, outside groups crushed the previous record for spending with $1.5 million on legislative races, including $400,000 spent on negative advertisements in a handful of state Senate races just days before the election. That record itself was crushed two years later when outside groups spent more than $3.7 million in Maine, financing the most expensive legislative races in state history.

Both parties have benefited, with corporate spending for Republicans and union support going to Democrats driving up the totals. There have also been wealthy individuals on both sides who have joined the financial arms race, including S. Donald Sussman, owner of the Portland Press Herald and other Maine newspapers.

At these levels, the outside money spent independently of the campaigns overshadow what the campaign and candidate do themselves. Spending by outside groups at these levels calls for more oversight. If the money can’t be limited, it can at least come into electoral politics with more transparency.

Groups that buy television ads should have to identify themselves, not just with misleading campaign names like “Citizens for Good Government,” but naming the source of the money. Voters who hear a negative message about a candidate should know if it was paid for by the pharmaceutical industry or a teachers union or another group with an interest in policy.

Corporations that spend the money should also have to disclose what they spent to their shareholders; unions should tell their members.

We hold campaigns and candidates accountable for every dollar they spend and every word they say. Why not hold the people who spend and speak on their behalf accountable, too? It would be illegal for a corporation to deliver a suitcase full of cash to campaign headquarters, so why is it legal for an organization to spend the same amount of money to influence the outcome of an election?

As we head into a new Election Year, we can expect to see even more money spent to influence Maine voters. Those voters should at least know who’s trying to influence them and why.