President Donald Trump’s campaign filed lawsuits Wednesday in Pennsylvania, Michigan and Georgia, laying the groundwork for contesting battleground states as he slipped behind Democrat Joe Biden in the hunt for the 270 Electoral College votes needed to win the White House.

The new filings, joining existing Republican legal challenges in Pennsylvania and Nevada, demand better access for campaign observers to locations where ballots are being processed and counted, and raise absentee ballot concerns, the campaign said.

However, at one Michigan location in question The Associated Press observed poll watchers from both sides monitoring on Wednesday. The AP called Michigan for Democrat Joe Biden on Wednesday.

Nevada, Pennsylvania and Georgia are undecided. The Trump campaign also is seeking to intervene in a Pennsylvania case at the Supreme Court that deals with whether ballots received up to three days after the election can be counted, deputy campaign manager Justin Clark said.

The actions reveal an emerging legal strategy that the president had signaled for weeks, namely that he would attack the integrity of the voting process in states where the result could mean his defeat.