Yeltsin's main opponents and would-be successors were already campaigning to replace the ailing president, and they fought hard to prevent Putin's emergence as a potential successor. Following the Russian apartment bombings and the invasion of Dagestan by mujahideens, including the former KGB agents, based in the Chechen Republic of Ichkeria, Putin's law-and-order image and unrelenting approach to the Second Chechen War soon combined to raise his popularity and allowed him to overtake his rivals.