WASHINGTON — The pharmaceutical industry, long an ally of Republicans, has increasingly worked itself into the good graces of the Democratic Party and by doing so has helped block the Democrats’ top prescription-drug initiatives.

In the year since they took over on Capitol Hill, Democratic leaders have been unable to pass either a bill allowing reimportation of drugs from Canada or a measure requiring negotiation of drug prices under Medicare. Neither is likely to reach the president’s desk this year. Lawmakers on both sides of these issues say the primary reason is the influence, now redirected, of the drug lobby.

Drug companies have gone on a hiring binge, retaining Democratic lobbyists in dozens of major firms. This strategy, which K Streeters call “clogging the system,” prevents adversaries from hiring anyone from those consultancies.

The drug lobby has also wooed congressional Democrats by plowing millions of dollars into helping with another Democratic goal: expansion of the children’s health program. In a detente with its traditional foes, the drug industry joined a group that included AARP and Families USA to buy about $7 million in ads backing the expansion of the program, under which states receive federal money to provide health insurance to families with children.

The industry’s main lobby, the Pharmaceutical Research and Manufacturers of America, known as PhRMA, paid for most of the group’s budget.

“They have all the money,” the policy director of AARP, which is no slouch when it comes to spending money on lobbying, John Rother, said. “They’re the ones who can write the big checks.”