Updated at 7:58 a.m.

The Texas Republican Senate primary is headed for a runoff, after Lt. Gov. David Dewhurst fell shy of 50 percent of the vote Tuesday.

Dewhurst will face former state solicitor general Ted Cruz, a favorite of the tea party, in the July 31 runoff. The winner of that runoff will be a heavy favorite to succeed retiring Sen. Kay Bailey Hutchison (R-Texas), after Democrats failed to land a top-tier recruit.

With 57 percent of precincts reporting, Dewhurst led Cruz 46 percent to 33 percent. Seven other candidates split the vote enough, though, to push the two into a runoff, according to AP.

Dewhurst was the favorite from the beginning of the campaign, earning significant establishment support and spending nearly $10 million of his own money before the primary.

Cruz, meanwhile, gained tea party support from groups like the Club for Growth and Sen. Jim DeMint’s (R-S.C.) Senate Conservatives Fund.

Despite that grassroots support, Cruz was outspent by Dewhurst and former Dallas mayor Tom Leppert, who finished third.

Dewhurst and allied super PACs spent more than $20 million combined, while Cruz and the groups supporting him spent less than half that.

The question from here is whether the tea party mobilizes against Dewhurst. A poll from Democratic-leaning automated pollster Public Policy Polling over the weekend showed Dewhurst starting the runoff with a very strong 59 percent-to-34 percent lead on Cruz, though many expect Cruz to close that gap somewhat.

Democrats had recruited retired general Ricardo Sanchez into the race initially, but he struggle mightily to raise money and dropped out of the race soon after.

The Democratic primary will also come down to a runoff, between former state representative Paul Sadler and educator Grady Yarbrough, a political newcomer.

In other congressional primaries held Tuesday in Texas, incumbent Rep. Silvestre Reyes (D-Texas) was defeated by challenger Beto O’Rourke in an El Paso-based district by a margin of 3,000 votes.

Reyes would be the fourth member of Congress this year to lose to a non-incumbent challenger, joining Sen. Richard Lugar (R-Ind.) and Reps. Jean Schmidt (R-Ohio) and Tim Holden (D-Pa.).

Two other incumbents survived primary challenges easily: Rep. Lloyd Doggett (D-Texas), whom Republicans targeted in redistricting, and Ralph Hall (R-Texas), the oldest member of the House.

In the lone Texas congressional district that is likely to be competitive after redistricting, former congressman Ciro Rodriguez held a 51 percent-to-36 percent edge on state Rep. Pete Gallego in the race to face freshman Rep. Quico Canseco (R-Texas). Canseco beat Rodriguez in 2010, but national Democrats favored Gallego in the primary, with the Democratic Congressional Campaign Committee naming Gallego to its ”Red to Blue” program for top recruits.