The three-day Conservative Political Action Conference that began Thursday at National Harbor in Maryland showcases a wealth of conservative spending power from more than 200 right-leaning donors, foundations, universities, think tanks and activists who have collectively doled out more than $1 million to help underwrite the event.

The American Conservative Union, which is hosting the conference for the 40th consecutive year, offers underwriters a sliding scale of benefits at rates ranging from $3,000 for exhibitors to $50,000 for event “partners.” The ACU also lists some 100 “VIP donors” on its website, without indicating how much each gave.

Nine “partners” collectively paid $450,000 to enjoy benefits such as hospitality room access, color ads in CPAC publications, exhibit space and invitations to private meetings, dinners and receptions, according to the website.

The partners include Judicial Watch, the National Rifle Association and the Tea Party Patriots.

The event’s 21 “sponsors” — who shelled out $19,000 apiece for a total of $399,000 — include the Washington Examiner and the Lynde and Harry Bradley Foundation, which according to tax records spent and gave out $40 million in 2011.

CPAC“co-sponsors” paying $8,000 apiece include the Susan B. Anthony List, which opposes abortion; the conservative grass-roots group Let Freedom Ring; and the Liberty University School of Law.

The ACU has long derived less influence from its budget than from its widely referenced scorecards and the CPAC gathering, which this year has drawn thousands of conservative activists and dozens of prominent elected officials and organizers.

But that is starting to change: The organization’s budget has quadrupled, from about $1.2 million in 2009 to $4.2 million last year, according to its tax filings.

Because the ACU is a 501(c)(4) social- welfare group, it is not required to report the names of its donors. But the group’s board includes the top executives of deep-pocketed players such as the NRA, which, according to tax records, had a $231 million budget in 2011; The Heritage Foundation, which had $80 million in expenses that same year; and Microsoft Corp.

The ACU’s political action committee raised and spent only about $120,000 in the 2012 election cycle, Federal Election Commission records show. But the ACU launched a super PAC in 2011 that raised and spent another $10,000 or so.

And the ACU itself made a $30,549 independent campaign expenditure on behalf of Republican Rep. Chuck Fleischmann of Tennessee, according to the Sunlight Foundation, suggesting that the conservative group may be gearing up to raise its campaign trail profile.