He also successfully introduced a law under which online providers can be prosecuted for offering a venue for content illegal in Germany – such as child pornography or Nazi propaganda – if they do so knowingly and it is "technically possible and reasonable" to prevent it.

[6] By January 2000, daily newspaper Süddeutsche Zeitung claimed that Kohl, angered by party chairman Wolfgang Schäuble's efforts to distance himself from the scandal surrounding secret payments to the party, was encouraging Rüttgers to make a bid for the leadership at the CDU's annual conference; instead, Angela Merkel was elected as Schäuble's successor[6] and Rüttgers became one of her four deputies, alongside Volker Rühe, Annette Schavan and Christian Wulff.

On the national level, Rüttgers was part of the CDU/CSU team in the negotiations with the SPD on a coalition agreement following the 2005 federal elections,[10] which paved the way to the formation of Chancellor Angela Merkel's first government.

Under the leadership of Merkel as party chairwoman, he was re-elected vice-chairman of the CDU in November 2006, this time alongside Roland Koch, Annette Schavan and Christian Wulff.

[14] However, by 2007, he and Roland Koch, his counterpart from the state of Hesse, agreed on approving a merger of their respective state-owned banks, WestLB and Landesbank Hessen-Thüringen (Helaba).

Shortly before the 2010 state elections, Rüttgers's public image was damaged by a party fund-raising scandal,[16] and local issues like education and the troubles of municipalities with heavy debt burdens were central to the campaign.

[17] He led his party to an electoral defeat; the steep drop of 10 percentage points compared with the previous election, in 2005, was even larger than most analysts had predicted and gave the Christian Democrats their worst postwar showing in that state.

[19] In May 2011, Deutsche Bahn nominated Rüttgers as executive director of the Brussels-based Community of European Railway and Infrastructure Companies (CER);[20] instead, Libor Lochman was eventually appointed to the position.

[35] Following the CDU's performance in the 2005 federal elections and the formation of the first government under Chancellor Merkel, Rüttgers blamed her campaign for talking "too much about flat tax and not enough about the people."

In response to Rüttgers's much-discussed phrase Kinder statt Inder, Germany's Green Party overwhelmed his Internet mailbox with thousands of messages.