In Dallas, two of Texas's most prominent Republicans — former President George W. Bush and Senator John Cornyn — gathered donors for Senate races across the country, yet left their own state's nominee, Ken Paxton, conspicuously off the invitation. It is an old story in politics: the party and the candidate share a banner but not always a cause. The omission speaks quietly but clearly about where establishment confidence ends and where a candidate must find his own footing.