The Quran talks about "strength" of religion in terms of proof. For example, Moses (a) was highest in the eyes of people, but people still rejected him.
The following can be concluded from the hadiths - in view of Ahlulbayt (a) are chosen by God.
(1) The true religion despite all the oppression Shiites and Imams (a) face, would remain strong in proof and evidence, all the way till the 12th Imam (a). The path would be clear, doesn't mean easy to follow, but it was clear and manifest and the word of God was high during up to the 12th Imam (a) for certain.
(2)After the 12th Imam (a) comes to be - it maybe - the state of "clearness" and "height" of God's word and rope, becomes not so high and strong. This hadith doesn't say it will happen, but it's possible. Meaning, believers should be worried about this and that they need to help God's religion if it's going to have a place of strength.
(3)The emphasis of Ahlulbayt (a) are from Quraysh, and there is no excuse to follow worst of Quraysh, when God's chosen is among the Quraysh. That, and it means, that Jesus (a) is not a successor of Mohammad (s) nor Elyas (a) nor any past or future person, but rather the Mahdi (a) is a Successor of Mohammad (s) from Quraish. This is possible, but there is another possible meaning to Quraysh.
(4) Some commentaries and there is evidence suggest that Quraysh never referred to a tribe in the normal sense, but was some sort of role like "police" and it had to do with protecting the Kaba. It was not just one tribe but many tribes that formed Quraysh. Quraysh is also not a nickname of anyone who is a root bloodline wise. The suggestion by some Tafsirs is that Quraysh in Suratal Quraysh means the God-fearing, and this perhaps is supported by the verse "And none of them are it's guardians except the guarding ones (against God's wrath and displeasure)." According to my research, this seems to be true. It's not even disputed by any scholar from what I know, just not well known among people because it's not talked about.