Look for Senator Clinton to spend aggressively in her easy-to-win re-election campaign that’s doing double-time as a presidential exploratory committee.

Mrs. Clinton has raised more than $40 million since she took office five-and-a-half years ago, and she’s spent about half her cash already. That’s a huge sum considering her paltry opposition. And the spending is about more than ensuring a big win in November.

By the time Mrs. Clinton is officially running for president, she’ll already have a vast campaign database with direct mail options and demographic data at her fingertips. Courtesy of contributors to her senatorial aspirations, Mrs. Clinton will have a hearty advantage in fundraising for national office.

The numbers are astounding. Mrs. Clinton raised $12 million between the last few months of 2005 and the first quarter of this year. Her campaign won’t speculate on what this quarter’s numbers will look like at the end of June for the usual reason that releasing any number will only raise expectations and give columnists something else to write about.

That said, the impressive fundraising numbers to date – far out-pacing the other 32 senators who also face voters in November – do raise expectations to predictably high levels. Mrs. Clinton’s experienced and forward-looking strategists don’t want the trajectory of cash to dip as the election approaches. This quarter will almost surely surpass the numbers raised in the last two three-month periods.

There’s already been plenty of talk about how Mrs. Clinton can easily transfer unspent Senate cash into a presidential campaign – because the contribution limit for both offices is $2,100 for the primary and a separate $2,100 for the general election. But there’s been less attention on how Mrs. Clinton can use the fruits of this campaign to make her presidential campaign run efficiently and lucratively.

Mrs. Clinton has spent millions of dollars on databases for fundraising and voter outreach. Those lists and cross-references and demographic details are hers to keep and use in the future. While her presidential opponents will be scrambling to make and buy and refine these highly important lists, Mrs. Clinton will only need to download a computer file.

And that file will be worth a lot. Just last year, Mrs. Clinton spent $10 million. Compliance lawyers and the communications team at Glover Park don’t come cheap, but they’re also not becoming millionaires on the campaign’s back. Direct mail, telemarketing, and the infrastructure to make them effective also don’t need to cost a lot. But Mrs. Clinton is spending a lot because she wants to win by a lot and have a lot left-over after the votes are counted November 7th.

Senator Schumer won his second term by a record margin of 71% to 24% four years ago against the barely known Howard Mills. This year, Mrs. Clinton could top that against Republicans John Spencer or K.T. McFarland.

Mrs. Clinton has already spent more than the $18 million Mr. Schumer shelled out – even before her field operations are at full strength and perhaps months before she buys television time.

“She’s had more of a consistent fundraising and campaign infrastructure,” pointed out her lead communications strategist, Howard Wolfson – who added the key point that “she’s done considerably more direct mail.”

Look for some of that in a mailbox or e-mail inbox nearby. And if you don’t respond now you’ll have another chance. The same lists will spit out your name again with the ’06 replaced with ’08.