In the immensely costly drive for the White House, Mitt Romney and President Obama can sometimes seem to be working on different orders of magnitude.

But not in terms of the total amount raised. Obama has raised millions of dollars, and Romney is drawing on a network of very wealthy donors to keep pace -- his $101.3 million July haul demonstrates how the presumptive Republican nominee has been able to demolish Obama's incumbent advantage in fundraising .

It is in the size of individual donations that the two campaigns often differ. A recent analysis found that the Obama campaign was relying more on supporters willing to give in small amounts, while Romney was pulling in larger sums from fewer people: those who donated less than $200 accounted for nearly half of the Obama campaign's take through April 30th versus 10 percent for Romney. But the majority of Romney's donors maxed out with the highest possible $2,500 donation.

That's in terms of direct donations. Fundraising events are a different story, and they allow Obama to tap into a powerful network as he seeks to raise the enromous sums of cash needed to fight against Romney, build a grassroots operation, and fend off a barrage of negative attack ads issuing from third-party groups like Crossroads GPS. 

Obama will be in Connecticut on Monday on a fundraising jaunt that features two tiers of backers. The first installment is a $500-a-head reception at the Stamford Marriott, anticipated to convene about 400 supporters. Musician Ben Harper is scheduled to perform at the gathering.

From there, Obama will travel to more rarefied air: a reception at the beachfront home of Harvey Weinstein, the prominent Hollywood producer. Guests will shell out $35,800 apiece to attend the event, which will be co-hosted by Anne Hathaway -- most recently seen donning a leather suit and battling Gotham's underbelly in the "Dark Knight Rises" -- and the screenwriter and producer Aaron Sorkin, whose show "The West Wing" has become a touchstone for idealistic liberals.

The Obama camp has repeatedly grown concerned with both Romney's fundraising prowess and with the clout of outside groups, like Super PACs, that have been able to pour millions into advertising campaigns. Democratic Senator Richard Blumenthal of Connecticut told the Hartford Courant that the fundraisers are necessary to counteract Obama's opponents.

"The president is facing a tsunami of super PAC and other undisclosed money,'' Blumenthal said. "This deluge of money he faces really requires him to do the kind of grassroots fundraising through parties and events that are happening in Connecticut. The special interest money he faces is unprecedented."