Under the leadership of President Hugo Chávez and now President Nicolás Maduro, the accumulation of power in the executive branch and erosion of human rights guarantees have enabled the government to intimidate, censor, and prosecute its critics, leading to increasing levels of self-censorship. Leading opposition politicians have been arbitrarily arrested, prosecuted, convicted, and barred from running for office. Police abuse, poor prison conditions, and impunity for security forces when they commit such abuses as arbitrary arrests, beatings, and denial of basic due process remain serious problems. Other concerns include lack of access to basic medicines and supplies—the result of problematic government policies—and continuous harassment of human rights defenders by government officials.