Democrats better find Senator Clinton an opponent fast. Their presidential frontrunner seems to have forgotten she faces re-election this year. An actual opponent would remind her. In the dozens of times I’ve covered Hillary Clinton since she was a First Lady first wooing New Yorkers, her discipline always stands out. Reporters can ask her anything and they get nothing she doesn’t want to give.

Snarky questions about her husband, quips about Senator Schumer’s reluctance to cede the spotlight, and queries about sensitive policy initiatives are always met with the same smile, pause, and graceful dance around substance.

The senator simply doesn’t let her words take the lead away from her message. She always appears acutely aware that her legion of enemies – whether “a vast right wing conspiracy” or just the state’s desperate Republican Party – are prepared to pounce. The constant scrutiny has been a constant force keeping the controversial carpetbagger on message. But as the state GOP’s efforts to challenge her re-election have collapsed, the senator’s discipline has taken a vacation from the reality that her words alone make news even when she’s said nothing newsworthy.

Mrs. Clinton wandered onto the plantation the other day because she forgot she’s on the campaign trail. There is simply no other way to explain her careless remark comparing the House of Representatives (in which she never served) to a slave-run work camp (on which she never suffered.) “When you look at the way the House of Representatives has been run, it’s been run like a plantation. You know what I’m talking about,” the senator complained at the Reverend Al Sharpton’s annual event commemorating Martin Luther King Jr.’s birthday.

Even the senator’s defenders acknowledge the time (King Day) and place (Harlem) of her remarks are as a significant as her message. The room full of black New Yorkers surely did know what she was talking about. But they didn’t need her help to appreciate the horror of involuntary servitude. And the senator didn’t need to use a room full of black New Yorkers to hype her claim that Republicans are both screwing up government while screwing Democrats.

Black voters like the Clintons – President Clinton won the Bronx during his 1996 re-election campaign by a bigger margin than any other county in the country. But just because black voters might tolerate the senator’s poor judgment this week doesn’t mean she won’t eventually pay a political price for picking lousy words to impugn Washington Republicans.

The short-term political damage will resemble nothing more than a windstorm that leaves a small mess in the backyard. But sometimes you don’t realize there’s a hole in the roof until the next storm rolls through. That is the risk for Mrs. Clinton, whose ambitions clearly go beyond imminent re-election to the senate.

The plantation remark reflects the reality of her re-election certainty. A cautious candidate would have realized her words were entirely gratuitous and lent nothing to the substantive debate about Washington politics. To be sure, Mrs. Clinton didn’t intend to be offensive. Senator Lott also didn’t intend to be offensive, though he clearly was, by suggesting the nation would have suffered less if a one-time segregationist had become president. And on a less substantive matter, Mayor Koch didn’t intend to be offensive when he complained there are no good restaurants upstate at the same time he wanted upstate voters to make him governor.

The issue these examples all have in common is judgment, and the lack of judgment politicians seem destined to make when they think they’re powerful enough not worry about staying in power.

State Republicans were in only slight array when Jeanine Pirro finally decided to challenge Mrs. Clinton for Senate. They dissolved into complete disarray when Ms. Pirro gave up and decided to run instead for attorney general. But in the long run, Ms. Pirro may hurt the senator’s long-term goals more by leaving her alone than she could have by engaging her all year long.

Mrs. Clinton proved her masterful campaign skills six years ago and she would have made mincemeat out of Ms. Pirro and her felonious husband. Ms. Pirro clearly realized that and made the wise choice to avoid becoming her party’s sacrificial lamb. With or without Ms. Pirro in the race, Mrs. Clinton would be poised for victory this year. But without Ms. Pirro in the race, she’s in the media spotlight far less often than she would be in a tradition campaign.

That worked for Mr. Schumer last year, when he faced token opposition and then won by a record margin. But Mr. Schumer wasn’t running for president two years later. Mrs. Clinton’s presidential campaign skills would be well oiled by a real re-election contest. She and her team would have the opportunity to test new themes and rehearse rapid response. Her ultimate victory would be seen as more legitimate, while now national Republicans – and potential Democratic opponents for President – will simply spin that she won big because she didn’t face big opposition.

The senator’s best option is to pretend this is a real race. She should make daily public appearances when she’s home from Washington, show up at the state Capitol in the height of budget negotiations, meet with newspaper editors across the state and do the sorts of things candidates do. Mrs. Clinton needs a refresher course on campaigning before hitting the national circuit full-time. She has the chance this year. I remain flattered that her last local television interview was with me. But that was 18 months ago. Someone else deserves a chance. The best way to act like a local candidate is make a round of appearances on local television shows. The questions might not be easy, but answering them sure beats plantation work.

Mr. Goldin’s political column appears weekly.