U.S. Sen. John Cornyn's reelection bid received a big cash assist from national Republicans late in campaign

Photo does not have a caption

U.S. Sen. John Cornyn, R-Texas, visited College Station in October, as part of his statewide bus tour. Credit: Amna Ijaz/The Texas Tribune

A super PAC supporting the reelection of U.S. Sen. John Cornyn, R-Texas, received a late infusion of big money ahead of the November election, including from the top super PAC aligned with Senate Republicans, according to a new post-election campaign finance filing.

Cornyn ultimately won by a decisive margin — 10 percentage points — but the 11th-hour rush of donations shows his allies were moving to keep up as his Democratic challenger, MJ Hegar, benefited from a flood of outside spending in the contest's closing days. Due to a loophole in campaign finance law, the super PAC did not have to report its post-Oct. 14 donors until after the election, concealing who was funding its activities in the race's final days.

The filing shows that the pro-Cornyn super PAC, Texans for a Conservative Majority, received $4.3 million from Oct. 15 through the election, most notably including $1.2 million from the Senate Leadership Fund. The group is closely tied to Senate Majority Leader Mitch McConnell, and it largely spends in the most competitive Senate races.