Upstart groups’ spending on Republican candidates in 2010 is “long overdue,” Republican National Committee (RNC) Chairman Michael Steele said Friday.

Steele said he welcomed the creation of groups like American Crossroads, the GOP-oriented organization affiliated with former Bush White House officials Karl Rove and Ed Gillespie, precisely because they can bypass the restrictions that constrain the RNC’s fundraising.

“Karl’s group, like many other 527s that are beginning to form within the Republican Party, is long overdue,” Steele said Friday on Fox News. “We’re 10 years behind on that. And I applaud them for taking the step to go out into the marketplace.”

Groups like American Crossroads and the U.S. Chamber of Commerce have found themselves under attack by President Obama and top Democrats in recent weeks for their work to influence Nov. 2’s elections. Because of a Supreme Court ruling earlier this year that loosened restrictions on corporate spending in elections, those groups are able to receive millions in corporate support without having to disclose the source of funding.

Those Democratic attacks have extended to allegations that those groups could be taking money illegally from foreign sources to spend on their political efforts. Those groups deny any such funding.

Steele stood up for the Rove-tied group and the Chamber, challenging Democrats to produce any evidence of foreign support for those groups.

“I’m tired of Democrats making these accusations. Put the proof on the table,” he said. “The reality of it is this is a legitimate-purposed organization. It is legitimately running its money, and let’s stop the craziness. Put up or shut up.”

Steele also denied that those groups had eaten into the RNC’s own efforts to raise money for the election, which are governed by limits on donations and are subject to Federal Election Commission (FEC) rules. The competition for dollars from GOP donors has been fiercer than ever this cycle, and the RNC slightly under-budget fundraising numbers for September, the second-to-last full fundraising month of the cycle.

“Karl Rove’s organization can raise unlimited funds from corporations, unlimited funds from individuals,” Steele explained Friday.

Updated 10:32 a.m.