Tension emerges between Congress, 2020 Dems on impeachment

In this April 4, 2019 file photo, Speaker of the House Nancy Pelosi, D-Calif., talks during a news conference on Capitol Hill in Washington. On the same day that House Speaker Nancy Pelosi urged rank-and-file Democrats to proceed with relative caution after the release of special counsel Robert Mueller’s report, Massachusetts Sen. Elizabeth Warren doubled down on her impeachment calls. (AP Photo/J. Scott Applewhite)

WASHINGTON — Some top Democrats vying for the White House in 2020 are clamoring for impeachment proceedings against President Donald Trump, but many of their congressional colleagues — who would have to manage such efforts — are far more wary.