In 1981, President Reagan offered S.I. Hayakawa, then California's senior senator, a job if he declined to run for reelection. We know this because Reagan's chief political adviser admitted as much on the record.
In 1997, then-Massachusetts Attorney General L. Scott Harshbarger negotiated a Justice Department post while he decided whether to run for governor. The Clinton White House did not want him to make that bid -- they wanted to clear the field for Rep. Joe Kennedy.
(Remember when William Weld was nominated to ambassador to Mexico? Same reason, same motivation. Jesse Helms scuttled this, but for reasons having nothing to do with presidential political interference.)
More recently, after Rep. Ben Gilman found his congressional district eliminated by redistricting in 2002, the White House tried to persuade him from challenging another Republican congressman in another district by considering him for an administration position. Karl Rove repeatedly intervened in Republican primaries. And Tim Pawlenty is not a senator because Rove urged him to run for governor instead.