Click here to watch "Ambition."

Up until Thursday, direct attacks over Barack Obama's connections with one-time domestic terrorist William Ayers have come largely from stump speeches by Sarah Palin and negative ads by outside groups. With Nov. 4 fast approaching, however, Republicans are intensifying their scrutiny of Obama's past.

Three ads released in the last two days, coupled with John McCain's most explicit condemnation yet of Obama's ties with Ayers, illustrate the tone shift. At a town hall meeting in Wisconsin Thursday, the GOP nominee described Ayers as "an old, washed-up terrorist" and said "we need to know the full extent of the relationship because of whether Sen. Obama is telling the truth to the American people or not."

"Ambition" (subscription), a joint spot from McCain and the Republican National Committee, devotes its first 10 seconds to an aggressive examination of the Illinois senator's ties to Ayers, who co-founded the radical organization Weather Underground in the 1960s. "Obama's blind ambition. When convenient, he worked with terrorist Bill Ayers," the announcer seethes. "When discovered, he lied." The last two-thirds of the ad switches focus to the financial crisis, which it blames on "congressional liberals." The announcer concludes with a reference to "bad judgment," aiming to link the two topics of the ad together.

Another solo RNC ad unveiled this morning, "Chicago Way" (subscription), chides Obama more generally over his "training" in Chicago's world of "shady politics" under "teachers" like Tony Rezko, William Daley and, of course, Ayers. After detailing Obama's alleged ties with these men ("Rezko got Obama in on a shady land deal," for instance) an announcer warns voters that "there's more you need to know." This ad echoes much the same message (and names) of McCain's earlier "Chicago Machine," though that ad did not reference Ayers.

The solo RNC spot is running in Indiana and Wisconsin, while the joint ad is supposedly running nationwide.

Along with these TV ads, McCain also released a 90-second Web video Thursday with more on the Ayers connection. As in "Ambition," the announcer here argues that the controversy raises larger questions: "Obama's friendship with terrorist Ayers isn't the issue. The issue is Barack Obama's judgment and candor."

Requests for comment from the McCain camp and the RNC were not returned.