WASHINGTON — Three of the four Republican presidential candidates will speak to the AIPAC conference by satellite on Super Tuesday.

Mitt Romney, Rick Santorum and Newt Gingrich each will address the American Israel Public Affairs Committee conference on the morning of March 6 before an expected 13,000 activists — a record number. The activists will spend the rest of the day lobbying Congress to ratchet up Iran’s isolation and intensify the U.S.-Israel strategic relationship.

Ten states will be voting in primaries on Super Tuesday, so the candidates will speak by satellite as they spend the day campaigning.

President Obama will address the conference on Sunday morning; Israeli Prime Minister Benjamin Netanyahu is slated to speak the next evening.

Much of the conference, as well as a planned Obama-Netanyahu summit, is expected to focus on aligning Israeli and U.S. strategies when it comes to Iran.

Israel’s “red line” on Iran is the Islamic Republic achieving the capability to build a nuclear device. For years the U.S. has had a red line of keeping Iran from acquiring a weapon.

The activists will press lawmakers on the Hill to embrace non-binding legislation that urges the administration to adopt Israel’s red line of “capability.”

AIPAC has refused to invite the fourth candidate, Rep. Ron Paul (R-Texas), to speak, citing the precedent of the Republican Jewish Coalition which shuns Paul for his steady record of voting against assistance for Israel and for his past instances of anti-Israel rhetoric.