The race for endorsements among Republican presidential candidates has been a slow one since we began keeping track of the endorsement primary earlier this year. Jeb Bush has sat atop our leaderboard, but many of his endorsements came before he officially announced his candidacy, and he’s received only three since Labor Day — all from House members.

But this week, Marco Rubio has shown signs of momentum, picking up endorsements from three fellow senators, including one today from Sen. James E. Risch of Idaho. In contrast to Bush’s 3 endorsement points since Labor Day, Rubio has received 22 — by far the most of any Republican candidate over that span.

In presidential primaries, endorsements are important as a sign of party support to both voters and other party officials. Of course, there’s still a long way to go, as Republican officials have been slow to coalesce around a candidate this year. In contrast, Democratic governors and members of Congress have rallied behind Hillary Clinton. Clinton has received 391 endorsement points. The GOP candidates have received 158 endorsement points combined.

Check out our live coverage of the GOP debate.