Sen. Cory Booker Cory Anthony BookerSunday shows preview: Lawmakers prepare for SCOTUS confirmation hearings before election The movement to reform animal agriculture has reached a tipping point Watchdog confirms State Dept. canceled award for journalist who criticized Trump MORE (D-N.J.) on Monday called on his followers to donate money in a bid to unseat Rep. Jefferson Van Drew (N.J.) after Van Drew announced over the weekend that he will switch his party affiliation from Democrat to Republican.

“@VanDrewForNJ has put his re-election prospects ahead of his duty at a time of crisis in our country,” Booker tweeted. “Let's bring courageous leadership back to NJ-02—please donate to support his eventual Democratic challenger.”

.@VanDrewForNJ has put his re-election prospects ahead of his duty at a time of crisis in our country. Let's bring courageous leadership back to NJ-02—please donate to support his eventual Democratic challenger: https://t.co/19u7MwGXg9 — Cory Booker (@CoryBooker) December 16, 2019

Booker linked to an ActBlue fundraiser page for the eventual Democratic nominee in Van Drew’s Atlantic City-area district.

Van Drew, who endorsed Booker’s 2020 presidential bid, reportedly made the decision to switch parties after a Friday meeting with President Trump Donald John TrumpBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Pelosi: Trump Supreme Court pick 'threatens' Affordable Care Act MORE. He has been one of the only House Democrats to vocally oppose the House’s impeachment inquiry, and was one of only two, along with Rep. Collin Peterson Collin Clark PetersonKate Schroder in Ohio among Democratic challengers squelching GOP hopes for the House The Hill's Campaign Report: 19 years since 9/11 | Dem rival to Marjorie Taylor Greene drops out | Collin Peterson faces fight of his career | Court delivers blow to ex-felon voting rights in Florida Peterson faces fight of his career in deep-red Minnesota district MORE (Minn.), to vote against House impeachment rules.

After the report of Van Drew’s party switch, five aides, including his spokesperson, announced their resignation. Democratic Congressional Campaign Committee (DCCC) Chairwoman Rep. Cheri Bustos Cheryl (Cheri) Lea BustosThe Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally DCCC dropping million on voter education program Clark rolls out endorsements in assistant Speaker race MORE (Ill.) tweeted a job offer from the DCCC to the aides Monday morning.